Mussels are steamed in boiling water for 4-5 minutes and remove from shells. Washed and boiled in salted water with bay leaf for 10-15 minutes. In the oil sauté chopped onions, carrots and celery until soft. Add the crushed garlic, flour and 1 cup mussel broth and boil on low heat for 10 minutes. Pour into the pan, top rank mussels, sprinkle with chopped parsley, salt and pepper and bake in the oven.