A friend tells me that there’s watercress growing in one of the wet bits of fen round here. I’ve been out combing the countryside and can’t find it – and my friend (who will become an ex-friend if this continues) will not tell me exactly where it is so he can eat all of it.
In the meantime, I’ve been buying my watercress in the shops and at the market. There’s plenty on sale at the moment, so head out and buy some. When you make this soup, try to find watercress with plenty of stalk – there’s a lot of flavour in the parts you wouldn’t necessarily use in a salad.
This soup is simple and delicious; it also freezes well, so you can make it in advance and bring it out when you have guests. When reheating, try not to bring it to a rolling boil – you’ll lose some of the lovely green colour if you overcook the watercress.
For a starter for four, you’ll need:
2 large bunches of watercress (about 150g)
1 large knob of butter
2 medium onions
2 medium-sized potatoes
800 ml chicken stock
150 ml double cream
Salt and pepper
Chop the onions roughly and sweat them in the butter until soft, but not coloured. Add the potatoes, chopped into medium dice and unpeeled, and keep everything moving around in the butter for five minutes until the potatoes are glistening. Pour over the stock, put the lid on the pan and bring to a gentle boil for about twenty minutes, until the potatoes are very soft.
Chop the watercress roughly (if you have any stalks left over from salads you’ve made, you can store these in the freezer until you make this soup and add these too) and add it to the pan, stirring for about a minute until the cress has turned a vivid green. Hold a bit of watercress back to garnish the soup with when you’re finished. Remove the pan from the heat and liquidise the soup in a food processor.
Return the soup to the pan and over a low heat add the cream and seasoning. This soup can be served chilled, like a Vichyssoise, but I prefer it hot from the pan with lots of crusty bread.