Clean the fish, cut them into thick slices and sort them into 2 groups, the firm-fleshed kind and the soft kind. Chop the onion; slice the leek; crush the garlic; scald, skin and slice the tomatoes. In a deep pan make a bed of the sliced vegetables and the herbs, season this layer. Arrange on top the pieces of firm-fleshed fish; season them and pour over them the oil. Add to the pan the wine and enough cold water or fish stock barely to cover the top layer of fish. Heat as quickly as possible to boiling-point and boil briskly for 8 min. Now add the soft pieces of fish, forming a fresh layer. Boil for a further 5 min. Meanwhile toast the slices of bread and arrange them in the bottom of the soup tureen or individual bowls. Pour the liquid over the bread and serve it as a fish bouillon. Serve the fish separately.