Heat the olive oil in a casserole, add the finely chopped onions and garlic, then the skinned and seeded tomatoes, cut into quarters, fry over a high heat, add the white wine, the bouquet garni, the salt and the pepper. Turn down the heat and cook uncovered for 15 minutes. Then add the cod fillets, salt lightly. Cook very gently, uncovered, for 5 minutes. Serve in the cooking casserole with Creole rice.