Mussels are cleaned and washed well, is steamed in boiling water and remove from shells. Clams thoroughly wash and leave to strain through a sieve dense water, which are steamed mussels. In fat sauté until soft chopped onions and grated carrots and celery, pour the water in which they are placed clams and boiled. Add clams and bay leaves. Once the soup boil for about 20 minutes, add the rice, chopped tomatoes and salt to taste. Before downloading it from the fire soup thicken with flour, eggs and yogurt. Serve with slices of lemon.