The only way to buy fresh vegetables, unless you want to pay the earth for them, is in season, and to buy them often so that they can be eaten absolutely fresh. There are dozens of different vegetables to be seen trundling in muddy lorries towards Covent Garden on any dark winter morning; parsnips, cabbages, sprouts, beetroots, carrots, endives, celeriac, swedes, celery, Jerusalem artichokes, red cabbage, turnips, winter spinach, onions, leeks, cauliflowers, spring greens and curly kale are all grown in Britain and are far, far cheaper to serve than the smallest handful of imported French beans. So, of course, are all the pulses that are so comforting on a cold day. Lettuces seem to struggle up all the year round, but they do become more expensive in winter and taste of less.