Method: Put the broad beans, celery, stock, thyme and salt and pepper to taste into a large saucepan and bring to the boil, stirring frequently. Skim off any scum with slotted spoon, reduce the heat to low and simmer very gently for about 1 and 1/2 hours or until both the vegetables are very soft and thoroughly cooked. Allow the soup to cool a little, then pass it through a sieve or puree it in an electric blender. Put back in the rinsed-out pan and adjust seasoning if necessary. Reheat the soup gently then pour into 4-6 warmed individual soup bowls. Garnish with a few small watercress. Serve at once, piping hot.
Ingredients: 500g broad beans, 4 cleaned and chopped celery stalks, 1.25L vegetable stock, 1 tablespoon chopped fresh thyme or 1/2 teaspoon dried thyme, salt and freshly ground black pepper, watercress springs.