150g/5oz organic butter beans
1.1L/2pt water for soaking
1.1L/2pt water for boiling
3 leeks
50g/2oz butter
1.1L/1½-2pt light stock (the water left after cooking the beans can generally be used here)
40g/1½oz fresh parsley, finely chopped
1 clove of garlic
juice of ½ lemon
1 tbsp white wine vinegar
salt and freshly ground black pepper

For the garnish:
4 tbsp natural yoghurt or single cream

Method
1. Soak the beans in water overnight, then drain and rinse well.
2. Bring them to the boil in fresh water and boil rapidly for 10 minutes in order to destroy any toxins on them.
3. Then partially cover the pan and simmer for a further 40 - 45 minutes or until the beans are fairly soft.
4. When cooked, drain them and reserve the stock for use later.
5. Wash and slice the leeks. Melt the butter in a saucepan and cook for a further 5 minutes, stirring occasionally.
6. Add the stock and simmer in a covered pot for 20 minutes, then stir in the parsley.
7. Allow the soup to cool slightly, purée and return to a clean pot.
8. Re-heat the soup gently adding lemon juice and vinegar to taste depending on how sharp a flavour you like.
9. Season generously with salt and freshly ground pepper.
10. You will probably find that you need to use quite a lot of salt.
11. Pour the hot soup into bowls and garnish each serving with 1 tbsp natural yoghurt.

Preparation time less than 30 mins

Cooking time 30 mins to 1 hour