Halfway through May, and the cast-iron soup pot still hasn't gone to its summer retreat under the stairs. The poor thing is in danger of getting metal fatigue. Early this week, I sat on the back step dozing in the hottest spring sunshine I can remember, then two hours later I was back in my fleece, softening garlic for a warming leek-and-potato number.
May has always been a tricky one for the cook. Supplies of locally grown produce are hit and miss, the weather is not sure if it wants to be winter, spring or summer and generally acts like it's having a nervous breakdown. Boil up oxtail soup, and the sun will beam down on you and bring your guests out in a sweat. Whiz up a bracingly chilled gazpacho, and some clever dick is bound to ask for their coat. At this time of year the cook has to be as schizoid as the weather.
Those too lazy to chuck a chook in the pot with a few root vegetables and boil it for an hour or so can turn the page now. The heart of a spring soup must be a clear, deeply flavoured amber stock. That way, you get to show off the new season's vegetables in all their whole, unpuréed glory. Spring vegetables are so beautiful you want to see them, not bash them to a pulp or hide them in a fog of cream.
Spring soup should have none of the murky, onion-and-wine depths of winter potages nor the pale mystery (is it watercress, do you think?) of a summer vichyssoise. Spring soup should twinkle and shine. Little broad beans like jade buttons, slices of violet artichokes (Italian but none the worse for it) and nibs of English asparagus need to look like jewels shining up through the golden broth. You get the best of both worlds, really, the soul-heartening broth and the fresh, clean zip of vegetables picked just before their prime.
Carrots, especially the junior variety barely thicker than a Marlboro Lite, have never really rung my bell. They are harmless enough in soup, though, sliced thin and on the skew, or if really, really infantile, dropped in whole. Silly prejudice apart, I suppose spring carrots really belong in any soup that claims to be truly seasonal. Turnips, too, though any bigger than a tangerine should be in the stock pot rather than the soup bowl.
I am not one to throw herbs around willy nilly, but almost any of the new flush of bright young leaves will do wonders for a clear chicken broth. Lovage, provided you don't go mad with it, offers an intense celery flavour, and lemon thyme and lemon balm do just what you would expect them to. Which makes them perfect for a soup whose point is to be fresh and bright. I use mint, too, the new un-hairy growth only, and bundles of coriander. The trick is to chop and add them at the very last minute. Young, soft-leafed herbs are not like woody thyme or bay, which require a long, slow braising - they give up their oils to the warm broth in a second. If you're lucky, their spice will be carried in the hot steam. Leave them in the simmering liquid too long and they turn to black mush.
Tiny fungi, such as miniature oyster mushrooms and the rare and exquisite morel (that's the one that looks like someone's attempt to crochet a gnome's pointy hat) are delicious in soup. They gently sponge up the broth and become thoroughly juicy. Even buttons, the mycological answer to blotting paper, can be forgiven their total lack of personality, soaking up the flavours of herbs and stock the way they do.
Light soups like these are something it is worth making at home because otherwise we would never get to eat them. No one is really making them commercially. On the rare occasion you find them on a restaurant menu you are unlikely to choose them over the salade chèvre or the chargrilled squid with rocket and chilli. If such elegant, understated dishes are to survive, we have no alternative but to make them ourselves.
You can purée spring vegetables if you've a mind to. I am not saying there is anything wrong with a steaming bowl of smooth asparagus soup, but I would draw the line at adding cream. What might mellow sweetcorn or mushroom simply sounds the death knell for a soup made with the season's new vegetables. The little things get smothered at birth. All I want right now is a hot, light broth to show off the dear little vegetables and pale new leaves on the herb bushes, and then maybe I can put my big soup pot away till autumn. Maybe.
A spring soup with herbs and lemon grass
No matter what vegetables you put in it, a soup as straightforward as this one can only be as good as the stock that is its heart and soul. The vegetables you use are very much up to what happens to look good when you get to the shops, but broad beans and, I think, asparagus should be in there somewhere. Serves 4.
a good litre of home-made chicken stock
a large stalk of lemon grass, or 2 of the little supermarket ones
150g podded broad beans
250g thin asparagus spears
a double handful of young chard or spinach leaves
essential herbs: mint, coriander
good herbs if you happen to have them: lovage, lemon balm, lemon thyme, etc
Pour the chicken stock into a pot and bring it to the boil. Put a pan of water on for boiling the broad beans. Meanwhile, peel away the tougher outer leaves of the lemon grass and slice each stalk across very, very thinly to give hundreds of paper thin rings. Tip them into the chicken stock, and if the stock has boiled, turn it down to a brisk simmer. The lemon grass needs to cook for a good 10 minutes to soften.
Drop the beans into the boiling water. They will need about 8 minutes or so, depending on their size (baby ones need little more than 5 minutes). Cut each stalk of asparagus into short lengths - nothing longer than the bowl of your spoon - and discard any tough ends. Drop the asparagus into your stock along with whatever you fancy and let it simmer to tenderness, a matter of 6 or 7 minutes.
While the asparagus is cooking, drain the beans under running water and pop them from their skins, then drop them into the stock. Wash the spinach or chard leaves (sand can get caught in the leaf folds) and tear them into reasonable sized pieces. Push them down into the stock and let them cook until soft and silky - maybe only a minute or two for spinach, a little longer for chard.
Chop the herbs roughly. You do, really, need both mint and coriander, but the rest are very much up to you. I like to add lemon thyme, even with the lemon grass already in there, for the ultimate freshness of taste. Ladle the soup in to warm bowls, then stir in the herbs. Serve very hot, so that the fragrant oils from the herbs rise up in the steam.
Nina Planck's chervil soup
Now here's an odd one. When I first came across this soup, I didn't really believe it. The ingredients are frugal, almost spare, and I worried it would have no depth. Yet it turned out to be a charming, gentle and yet wholesome broth - perfect for this time of year. The recipe comes from a lovely new book, The Farmers' Market Cookbook by Nina Planck (£18.99, Hodder & Stoughton), that celebrates the produce of our burgeoning local markets. Serves 2.
100g chervil leaves, chopped
extra chervil for stock
400g waxy potatoes, peeled and diced
2 reserved for the stock
1 onion for stock
1 shallot or 2 spring onions, finely chopped
1 tbsp olive oil
2 tbsp best olive oil
Make the chervil stock. Bring to the boil 1 litre of water with the chervil stems, the extra chervil, 1 potato, quartered, and the onion, quartered. Cook for about 20 minutes, then strain.
In a large saucepan, sweat the shallot or spring onions in the olive oil. Add the chervil stock and the diced potatoes and bring back to the boil, then reduce the heat to a simmer till the potatoes are half done. Add the chopped chervil leaves and simmer until the potatoes are soft but the chervil is still bright (about 5 minutes). Do not overcook.
Stir in the best olive oil, check the salt and serve.