Under the head of baking we come to that excellent method of treating fish which is familiar to most of you as au gratin. The cook can, in this way, produce very pleasant results with very little toil. You can commence as plainly as possible, and go on to the most elaborate and fanciful dishes, the principles in all being similar. The fish, to begin with, can either be whole, in fillets, or slices. The flat gratin dish should be well buttered; minced mushrooms, various shellfish, chopped anchovies, finely minced parsley, shallot or chives, and such sweet herbs as you can command, are often used for the more elaborate compositions; whilst parsley, shallot, and butter alone, with fine bread crumbs, will suffice for the plainer dish for ordinary occasions. A fish broth made from the heads, liver, skin, fins, bones, and trimmings of the fish, with a few peppercorns, an onion sliced, with or without a glass of any light white wine, like chablis, hock, or sauterne, should be gently poured round your dish when it is packed ready for the oven: but the liquid ought never to come up to the level, quite, of the top layer of the fish in the baking-dish.
A slight sprinkling of grated Parmesan or Gruyère is often recommended for these dishes.
Fillets of anchovies, shrimps, and prawns, form, with oysters, scallops, and mussels, the most appropriate garnish for an artistic au gratin, while essence of shellfish, and chablis should be judiciously introduced to moisten the combination.
Fishes carefully stuffed, and baked whole, are generally nice: it is a method particularly well suited to fresh-water fish, and a pleasant way of cooking a haddock, sea-bream, gurnard, or a dish of whitings.
The white fireproof china baking dishes are most handy for cooking fish after this method, for it should be noted that the fish should be served in the dish in which it is baked without changing.