This recipe is inspired by one in Recipes from Baghdad.
Boil the beans in salted water until tender, and drain. Beat the egg into the yoghourt so that it does not curdle when it is cooked, and pour it into the pan with the beans. Add rice, garlic, salt and pepper and simmer gently, stirring, for 10 minutes.
Serve hot or cold, sprinkled with mint if you like.