Drain the soaked peas and set aside. Heat the oil in a large pan, add the onion and apple and sauté for 4 mins until softened. Add the ginger and curry paste and stir in the peas. Stir well.

Add the stock, bring to the boil, cover and simmer for 1 hour until the peas are tender. Transfer to a food processor, add the watercress and blend until the soup is fairly smooth. Season to taste and serve with crusty bread.