According to nutritionists, dietitians and food fashion gurus, nothing beats the Mediterranean diet. It looks, of course, wonderfully colourful and appetising, but, re-created in Britain, it never seems to taste authentic. This is partly because the vegetables chefs buy here don't stack up well when measured against the produce available in the markets of Italy, Spain, France, Morocco and the Lebanon.
Let's be clear: cooks all over the Mediterranean buy produce supplied by the agro-industrial giants and, wherever it may originate from, only a small proportion is organic. What still exists, though, is a choice. The chef or the amateur cook can decide whether they want to use produce from a factory or from a peasant farmer.
Explore any Italian or Spanish market's vegetable stalls. The chalked-up label will tell the shopper a price, a variety and a place of origin. It's meaningful information that consumers understand.
We have the same information in our wholesale system. What is missing for many chefs is an awareness of what location or variety brings to a raw material. "Peppers, Holland" gives a clear message: grown intensively under glass. It's hardly inspiring. "Roma tomatoes" ought to send a similar signal - likely to be grown by the tonne on large-scale farms.
There are, though, vegetable varieties that are distinctive, that are especially good to eat. Only by recognising these, buying these and cooking with them can chefs hope to create authentic Mediterranean flavours in our colder climate.
They divide roughly into three groups: large and medium-sized slicing tomatoes, cherry tomatoes and elongated or tapering cooking (plum) tomatoes.
The best-known French tomato is the Marmande. It can grow to more than a pound in weight. It can be greenish at the top. Sometimes it splits close to the stem. These appearance defects don't have any bearing on eating quality.
Sliced open, it looks more fleshy than typical British tomatoes. Its taste has a good balance between sweetness and acidity that makes it suitable for salad use and for cooking.
Almost torpedo-shaped, the San Marzano is the fashionable Italian cooking tomato of the moment. Originating in the south, near Naples, it used to be the classic pizza tomato. It's very fleshy and well-flavoured. A modern "improved" version of this, the Super Marzano, is more widely available. A smaller variety of the San Marzano, the size of a cherry tomato and sometimes sold on the vine, has an intense, sweet flavour.
The canning industry works with different kinds of Roma, less elongated, almost oval in shape. It's not strongly flavoured. Philip Britten imports it fresh but suggests that for sauces the best canned brands are as good or better, because they're picked and processed under ideal conditions.
Italian Cuore di bue tomatoes, sometimes called Monserrat in Spain, are large, pink and fleshy, and an ideal variety for raw gazpacho-type dishes. They are less acid than Marmande, but sweetish and juicy.
The terms "vine tomatoes" or "cherry tomatoes" are no guarantee of flavour even though the fruit may have been harvested ripe.
- Seasonality: Tomatoes are an all-year-round crop, but the best, those that have cropped outdoors, are in the markets now and until the end of September.
Courgettes Courgettes and their by-product, courgette flowers, taste relatively bland. There's little benefit to the chef in importing these from the Mediterranean. What matters more here is freshness and, depending on the use, size. For rustic dishes such as ratatouille, buying finger-length courgettes is a wasted expense, but the smallest ones taste best when rapidly sautéd.
- Seasonality: spring to autumn
Aubergines The large, almost balloon-shaped aubergines we see most often in the UK drink up oil and reduce to a fraction of their original size when cooked. They are sold throughout Europe, but they aren't the only variety. In Italy, the violetta appears in markets either long, thin and purple or as a familiar aubergine colour or as a dwarf variety.
The tonda comune di Firenze, a pale, round, purple hybrid with fewer seeds than most aubergines, doesn't absorb oil to the same extent as other kinds, nor does it lose its shape when cooked. The skin is thinner, too. It's an ideal component for vegetable stews, but would be less suited to aubergine caviar (baba ganoush).
- Seasonality: spring to autumn
Spain is especially rich in pepper varieties. The bottled, smoky-red piquillos are a delicacy, but the small, fresh, green pimientos de Padron or the straggly, pointed varieties from Catalonia and the Basque country are quite unlike the Dutch bell peppers we mostly import.
Pimientos de Padr¢n, green, thin-skinned and tender, are available, thanks to poly-tunnels, from the early spring until winter. Quickly saut‚d and dished up piping hot, they're a speciality of bars.
Longer, often mottled varieties, such as Biscayne, are sweeter and more suited to slicing and stewing.
Italy imports some of its peperoni from Spain, but also grows large peppers in Sicily, Campania, Veneto and a special variety, the peperono quadrato di Asti, in Piedmont.
- Seasonality: spring to autumn
The choice of onions is much wider in the Latin countries than here. Some, such as the cipolla rossa di Tropea, have an ancestry going back to pre-Roman times. For practical purposes, though, origin matters less than style.
- Sweet Spanish onions are better for tarts, pissaladière and onion confit. They are usually round but can be flatter and pink as well as yellow.
- Red onions are quite mild. They look good in roast vegetable combinations.
- White onions: the small silverskins are either for pickling or for stewing whole to accompany dishes such as coq au vin.
- Otherwise, any all-purpose onion will do the job.
Ligurian basil Most cooks who have tried it say that Ligurian basil is the best-flavoured of all. It's not exported to Britain because, pulled up by the roots and sold in bunches, it doesn't travel. Genoese cooks, who make pesto from it, claim it's unique because it's harvested, stalks and leaves together, before the plant has a chance to flower, when it's full of sap.
New-season garlic Against most chefs' expectations, perhaps, new-season garlic doesn't have a strong flavour. It's mild enough to eat raw in salads. In cooking it doesn't need blanching. Nor does it have the green germ you find in old garlic that is starting to sprout.
Most commercial produce (much of it imported from China) is mechanically dried so as to extend its shelf life. Fresh garlic is white and juicy when sliced.
Many chefs find it necessary to blanch garlic in water or milk before using it. This is unnecessary when it's at its freshest, but may be preferable from the autumn onwards.
- Seasonality: By the end of August the new garlic season will be over, but it's still better to buy air-dried strings of garlic than the industrially processed variety.
Puree d'ail nouveau Put the peeled cloves of four heads of garlic in a pan with 120ml whipping cream, 120ml water and salt. Boil gently till soft - about 15 minutes. Drain, pur‚e, beat in 40g butter. Season with freshly ground white pepper.
Five years ago Philip Britten was head chef at the Capital, arguably the best hotel restaurant in London. He left his job after setting up Solstice, a company that sources and supplies international produce to caterers.
"When I started," he confesses, "I thought I knew a lot about vegetables, and probably did for a chef, but I knew very little compared to what I do now."
With agents in many of Europe's best markets, from Barcelona to Rungis and Florence, he sources ingredients with a provenance, chosen on the basis of their variety and the way they have been grown.
Their taste, he insists, counts far more than a standard size or shape or blemish-free exterior.
Having built up a business that delivers to high-profile clients such as Mark Hix, at London's Ivy restaurant, and Antony Worrall Thompson, Britten launched a new business this spring, Oscar Samuel, which prepares and delivers staff meals to restaurants.