What to Eat: Food that’s good for your health, pocket and plate

• Dress the more bitter leaves, such as radicchio and curly endive, with nut oils (walnut or hazelnut) and cider or sherry vinegar.

• Use whole, crunchy leaves (such as Little Gem or Cos) as a ‘plate’ for hot minced pork or duck that has been stir-fried, mixed with a little ground toasted rice, fresh coriander and mint leaves, then dressed with lime juice, palm sugar and fish sauce in the style of an Asian ‘larb’ (meat salad).

• Salad leaves become the basis for a meal if you put them together with crisp-fried bacon, soft-boiled egg and croutons of fried bread.

• For a fail-safe, classic vinaigrette, use three parts extra virgin olive oil to one part red or white wine vinegar. To obtain a good emulsion, combine the vinegar with a little smooth mustard, sea salt and pepper before whisking in the oil. If you like a sweeter taste, add a drop of honey to the mustard and vinegar mix.

• Sweat watercress in butter with some onion and potato and/or peas, add stock and liquidize to make a verdant, punchy, easy soup.

• Braise halved Little Gem or baby Cos lettuce in butter and chicken stock until soft and juicy, adding a little cream to finish off.

• Heads of chicory or crunchy lettuce hearts, either blanched or steamed, make an unusual winter gratin when wrapped in thin slices of ham and baked in a béchamel sauce.

Are lettuce and salad leaves good for me?

Leafy salads are sometimes dismissed as being mainly water, which is true up to a point, but also misleading since they also provide valuable levels of antioxidant vitamins, minerals and trace elements that we particularly benefit from because we eat them raw. Lettuce has also figured in traditional medicine for centuries as a sleep-promoting food.

Levels of micronutrients vary from one type of salad leaf to another. Cos lettuce, for instance, is packed with vitamin C. Watercress stands out as a nutritional treasure trove. It is loaded with vitamins C and E, and beta-carotene which help neutralize the damage done by harmful free radicals that can predispose the body to disease; folate, which helps prevent birth defects; and zinc, which supports the immune system. All salad leaves contain these, but at lower levels. Watercress has a time-honoured place in traditional medicine as a tonic, purifying food and as a remedy for skin problems.

The nutritional value of salad leaves starts to diminish as soon as they are picked so it is important to eat them as fresh as possible. Research suggests that bagged salads sold in puffy ‘pillow’ packs filled with modified atmosphere have fewer vitamins and folate than the freshly cut equivalent. This could be because although the modified atmosphere keeps the leaves looking fresh and green beyond their natural shelf-life, some nutrients are depleted by the storage process. This deterioration is likely to be even more rapid in bags that contain leaves that have been torn and cut.

Bags of salad leaves that are sold as ready-to-eat will have been washed in water. Unless they are organic, this water usually contains chlorine, an oxidizing disinfectant, which may also reduce their micronutrients. Some retailers now have their salad leaves washed in spring or ozonated water instead to improve the taste and reduce the chance of chlorine by-products lingering on the leaves. But unless your salad bag label says otherwise, assume that chlorinated water has been used. It is always a good idea to wash bagged salad leaves even if they are ready-to-eat as an extra precaution, both against food poisoning bugs that might have colonized the packs during processing, and to rinse off any lingering chlorinated water.

Due to their open leafy shape, lettuces and salad leaves are particularly likely to trap pesticides. Since the early 1990s government testing of UK-grown salad leaves has revealed an ongoing problem with pesticide residues, so much so that the government now checks them on a regular basis. This residue problem has been most evident in lettuces, both UK-grown and imported, that have been cultivated in glasshouses and in polytunnels, rather than the open field, because they get particularly heavy fungicide treatments. The protected environment creates the perfect climate for the development of rot and the carry-over of disease from one crop to the next.

Follow-up action taken by the authorities against growers producing lettuces with unacceptable levels of pesticides has reduced the incidence of residues somewhat, but lettuces are still routinely found that have multiple residues of various pesticides. Illegal use of pesticides not approved for use in the UK is often also detected. If you want to reduce your exposure to pesticide residues, there is a strong case to be made for buying organic salad leaves. Hardly any pesticides are approved for use in organic growing and no pesticide residues have been found in recent years in organic salad leaves.

How are lettuces and salad leaves grown?

Lettuces and salad leaves were traditionally grown outdoors in open fields, but nowadays many of the lettuces and leaves we eat, whether home-grown or imported, are cultivated in polytunnels or glasshouses. Growing salad leaves under some sort of cover allows growers to extend the growing season because it keeps the crops warmer and protects them from weather damage. In recent years there has been a technological revolution in growing some salads under cover in a temperature-controlled environment using soil substitutes (see PEPPERS/How are peppers grown?).

British watercress is grown in a different way to other salad leaves. Traditionally foraged from streams, these days it is cultivated in shallow, gravel-lined concrete beds in a gentle flow of water from natural springs and underground bore-holes. In the UK, the key watercress-growing areas are Hampshire, Dorset and Wiltshire. As the cress grows in water, it doesn’t freeze in winter as tender, soil-grown green leaves would do. This means that although watercress used to be considered a late spring and summer crop, we now have year-round watercress production.

Are lettuces and salad leaves green choices?

From an environmental perspective, it makes no sense to eat lettuces and salad leaves that have been imported from abroad. These have to be trucked long distances in refrigerated vehicles, which uses up a depleting resource – oil – and contributes to climate change in the form of vehicle emissions. As a wide variety of lettuces and salad leaves can be grown in the UK for the best part of the year, there is no need for environmentally destructive imports. Watercress is a ‘green’ choice in more than one respect: watercress beds provide a particularly attractive natural environment for kingfishers, warblers and other rare birds and encourage otters to set up home in nearby rivers. In wintertime, when the availability of UK-grown leaves and lettuces is more limited, a more environmentally aware approach is to ring the changes with native seasonal vegetables.

Where and when should I buy lettuces and salad leaves?

Salad leaves used to be thought of as a summertime food. Now we tend to think of them as something we can eat year round. If you want to eat UK-grown salad leaves and lettuces, then the selection will change throughout the year and be smaller, but still worthwhile, in the winter. When buying salad leaves, use your common sense and think seasonally. As a rule of thumb, the more bitter-tasting leaves such as chicory will continue to grow in Britain in winter and many other types, such as landcress, watercress and lamb’s lettuce, make excellent winter salads. More tender leaves and lettuces don’t naturally thrive outdoors in the UK except from early summer until autumn. Supermarkets offer a year-round availability of salad leaves and lettuces. In the winter months they will be imported, usually grown in glasshouses and polytunnels in North Africa and southern Europe.

If you feel daunted or bored at the thought of getting through a whole head of lettuce, check out the fresh mixed leaves selections on farmers’ markets stalls, from box schemes, farm shops and natural food stores which usually offer a more interesting array than the supermarket equivalent. Another way to transform your supply is to grow your own ‘cut-and-come-again’ salad mix, sometimes called ‘misticanza’ or ‘saladini’ in a container (on a patio, balcony or windowsill) or in the garden. Even the smallest space will give you a varied summertime crop that you can snip away at, enlivening other more humdrum lettuces and leaves.

Will lettuces and salad leaves break the bank?

Weight for weight, it is much cheaper to buy a whole lettuce and wash it yourself rather than just stumping up for a bag of salad leaves. At a glance, the contents of these bags might look quite adventurous, but on closer inspection, you will probably find that they are padded out with cheaper substitutes – red cabbage instead of radicchio, for instance – which makes them unexciting and poor value for money. There is no point in paying more for ready-washed salad leaves because it is best to wash them yourself at home as a health precaution.

If you think you can’t get through a whole lettuce at a time, simply strip off a few leaves and return the heart to the salad compartment of the fridge. If you want to use a mix of leaves, but can’t see how you can use them all at once, you can wash them all together, take what you want for that meal, then keep the rest inside a plastic salad spinner with a lid on in the fridge where, if truly fresh to start with, they should keep for a couple of days. If you live on your own, or in a smaller household, eat small quantities of one salad at a time, say lamb’s lettuce or mustard cress, and then choose a different leaf next time. This way you avoid waste and get your salad variety, not in one bowl, but over a period of time. The same ‘mix’ of salad leaves inevitably becomes tedious if you never vary it.

Tender, young pea shoots and tendrils are all the rage for salads and sell for a premium price. Rather than shelling out for them – excuse the pun – if you don’t have a garden, then you can grow your own either indoors, or on a patio or balcony. Just fill a container with compost in spring or summer, plant some shop-bought dried peas, put them in a light place and then water them regularly. The shoots will pop up in around two weeks and you can harvest the shoots and tendrils for weeks, just like a cut-and-come-again lettuce.

THE EVERLASTING ICEBERG

Salad leaves have always featured in our diet. In 1699 the English gardener and diarist John Evelyn’s book, Acetaria, catalogued an astonishing diversity of plants that could be used for ‘sallet’. He also recommended ‘a particular Composition of certain Crude and fresh herbs, such as usually are, or may safely be eaten with some Acetous Juice, Oyl, Salt, &c. to give them a grateful Gust and Vehicle’: what we now know as a French dressing or vinaigrette.

The dark ages for British salad leaves were in the post-Second World War years when a salad typically consisted of a couple of flaccid leaves of curly lettuce, topped with boiled egg and tomato, temptingly garnished with that peculiarly British condiment known as ‘salad cream’. When the American iceberg lettuce arrived in the 1970s, it felt revolutionary. We devoured them with enthusiasm despite their almost total lack of flavour because they delivered that welcome juicy crunch. The cabbage-like iceberg could be kept in the fridge, apparently fresh, for weeks on end. For a nation that ate green salad infrequently, more out of a sense of duty than anything else, the everlasting iceberg was just the job.

Throughout the 1980s and 1990s, restaurants began to showcase more exciting salad leaves such as curly endive and oak leaf lettuce, stimulating consumer demand for what we took to be foreign varieties. The dreaded iceberg has now been relegated to crummy sandwich bars and we have embarked on a love affair with rocket. British salad leaves have perked up no end in recent years as neglected native varieties have been complemented by fascinating newcomers from as far afield as Japan. This diverse selection is now in small-scale commercial production around the UK.

Mushrooms, cultivated and wild

(large white, button, chestnut, portobello, oyster, enoki, shiitake, porcini (ceps, boletus) chanterelles, morels)

Mushrooms, or edible fungi, come in lots of different forms, each with its own colour, scent, texture and flavour. Wild chanterelles, for instance, have an almost apricot-like perfume, while shitake can have a smoky presence. Large black portabello and field mushrooms are distinctly meaty. Chestnut mushrooms have more of that woodland taste than the white button sort. But, taken as a family, they share certain characteristics. They taste earthy and savoury, and are one of a few plant foods capable of producing the rich flavours found in meats and cheeses. Japanese people refer to this quality as ‘umami’, and consider it to be the fifth component of taste along with sour, sweet, salty and bitter. Mushrooms have this rich savoury flavour because they contain glutamic acid, a naturally occurring flavour enhancer – not to be confused with the synthetically made food additive, monosodium glutamate (MSG) – along with other natural flavour enhancers. When mushrooms are dried, these natural flavour enhancers are intensified, which is why dried mushrooms pack more punch than their fresh equivalents.

Whatever type of mushrooms you are buying, the same rule applies: look for firm, dry heads and avoid any that look wet or shiny as this is a sign that they are starting to decompose.

Things to do with mushrooms

• A basic liquidized soup made with fresh mushrooms, onion and stock is transformed by the inclusion of a couple of soaked, dried porcini before blending.

• Fill large flat mushroom heads with herby butter (try thyme or tarragon), top with breadcrumbs and bake or grill until they are soft below and crunchy on top.

• Sauté mushrooms with strips of bacon or pancetta, some fresh sage (if you have it), season with black pepper and sea salt, and add thick cream and chopped parsley: an instant sauce for spelt, pearl barley or pasta.

• Brush toasted sourdough bread with olive oil and a thin layer of Dijon mustard, then top with a pile of pan-fried wild or cultivated mushrooms, tossed with chopped tarragon, and a fried egg for a quick, filling supper.

• You can turn the remains of a beef stew into a cheat’s stroganoff by stirring in sautéed, sliced mushrooms and soured cream. A dusting of chopped dill adds sparkle.

Are mushrooms good for me?

Mushrooms may not look that promising, but they have many nutritional strengths. They are a good source of soluble fibre, which slows down the speed at which sugar is released into the bloodstream, and B vitamins, which provide energy and support brain function. While it used to be thought that vitamin D was not found in plant foods, a plant sterol – ergosterol – has been identified in mushrooms, which converts to vitamin D when exposed to light. Vitamin D is increasingly being recognized as protective against a wide range of diseases and it is thought that many British and Irish people do not get enough of this for optimum health. For vegetarians especially, mushrooms are a welcome source of vitamin D.

Mushrooms are also a good source of key minerals such as copper, which helps blood cell production, and selenium, which is thought to be protective against certain cancers. Some research suggests that the fatty acids in mushrooms, particularly conjugated linoleic acid, may inhibit breast cancer cell growth. Other research has suggested that certain mushrooms, such as shitake, have immune-modulating effects; that is, they help regulate and strengthen the immune system.

Cultivated mushrooms are usually treated with fungicides while they are growing. Use of insecticides and chemical disinfectants, such as chlorine, is also routine for sterilizing mushroom sheds between growing cycles. If you would rather that your mushrooms weren’t grown this way, choose organic. Organic growers are not allowed to use these chemicals and their mushroom sheds must be steam-cleaned.

Eating mushrooms collected from the wild is a risky business as it is quite easy to confuse edible and poisonous types. However enthusiastic you are about foraging, it is vital that any you intend to eat have been correctly identified by a reliable, experienced person – a poisonous one can kill you.

How are mushrooms grown?

The cultivated mushrooms we eat are nearly all grown in Britain and Ireland. They are cultivated in indoor environments that mimic the natural stages of mushroom growth. Many types of mushroom can be grown this way, not only the familiar white- and brown-capped types such as button and chestnut, but types that are often thought of as wild, such as oyster mushrooms and shitake. First a growing medium, or compost, is prepared, typically a mixture of straw, gypsum (a mineral used to make plaster) and poultry litter. Poultry litter is a euphemism for bedding cleaned up from the floor of indoor poultry production units. It consists of straw, poultry droppings (manure), feathers and possibly uneaten feed. Compost for growing organic mushrooms is mainly made from organic straw, but sometimes sawdust or woodchips are used. It can also contain manure from organic, but not intensively farmed, livestock.

Once mixed, the compost is allowed to decompose naturally for a time, then it is pasteurized to kill off any potentially dangerous bacteria or moulds. This method produces the crumbly dark compost that you see clinging to the base of mushroom stems.

The compost is then inoculated with mushroom spores (mycelia) and put in bags, or spread out on trays, blocks and shelves, in hot, humid, dark sheds. This encourages the spores to multiply throughout the compost. When the spores have thoroughly colonized the compost, it is covered with a layer of ‘casing’, usually peat mixed with sugar beet lime, and the temperature is reduced to encourage the mushrooms to fruit. The mushrooms come through in flushes, and are harvested by hand in low light. Some types of mushroom can also be grown on inoculated logs.

Wild mushroom spores spread underground in woods, then, given the right weather conditions, they ‘fruit’ or produce edible mushrooms in among vegetation and decaying leaf mould. Wild mushrooms are harvested by foragers, usually for cooking at home, although some semi-professional foragers supply them to shops and restaurants.