A Persian combination.
Soak the beans in water for an hour. Fry the onion in oil until golden in a large saucepan. Add the prunes and the drained beans, cover with water, add spices and pepper and cook until the beans are tender (from ½ to 1 hour) and the water much reduced, adding salt when the beans have softened. Wash the spinach and remove thick stems. Put it in the pan and cook, turning it over and stirring, for