Commodore Garnish

This is not a dish but a garniture — a set of composed elements arranged in heaps around a platter of fish, in the classical French service Oscar's kitchen worked in. The entry assumes you already know four other preparations, so read it as an assembly list.

• Mussels must be cooked and shucked firstThe instruction to dip mussels in sauce, crumb and fry them presumes they have already been steamed open and taken from the shell. A brief fry only sets the coating; it will not reliably cook a raw mussel through. Discard any that do not open during steaming.
• Villeroy sauceSauce Villeroi is a very thick allemande or velouté, usually enriched with truffle or mushroom essence, cooked down until it will cling to a cold item and set firm. Chill the coated mussels until the sauce is solid before crumbing, or the breadcrumbs will slide off in the fat.
• Matelote sauceA red-wine fish sauce built on fish stock with mushrooms and small onions, finished with butter. It signals that this garnish was designed for fish, not meat.
• QuenellesForcemeat dumplings, here of crayfish, poached rather than fried — shaped with two spoons and dropped into barely trembling salted water or fish stock. Water at a rolling boil breaks them apart.
• "Boiling lard or other fat"Deep-frying, roughly 350-375F. The recipe treats lard as one option among several; a neutral high-smoke-point oil behaves the same way. Fry in small batches so the temperature does not crash and soften the crumb.
• Whole trufflesThe recipe calls simply for large whole truffles, boiled; whether fresh or preserved is not stated. Preserved whole truffles in their liquor are the closest practical equivalent today; truffle oil is not.
• No quantities givenThe entry says only 'equal quantities' and 'the required quantity', leaving the garnish to be scaled to the fish it surrounds. As a rough working guide for a platter serving six, figure on one croquette, one quenelle, one fried mussel and a slice of truffle per portion, set in small mounds around the dish as the recipe directs rather than scattered.
• CrayfishFreshwater crayfish, cooked and picked; the shells were traditionally pounded into crayfish butter to enrich the croquette and quenelle mixtures. Cooked crayfish tails, or shrimp at a pinch, will stand in.