Peanut Chilli Soup

3 cups vegetable, chicken or beef stock 1 medium onion, coarsely chopped 1 large leek including 2 inches of the green top, coarsely chopped 2 medium carrots, sliced into 1/2 inch thick rounds 1/4 cup uncooked long-grain white rice 1 lump of Cornish chilli sauce 1/2 cup smooth peanut butter Combine the stock, onion, leek and carrots in a heavy saucepan and bring to a boil over high heat.