Oysters, Viennaise

Ranhofer writes for a brigade that already has velouté, lobster butter and shucked oysters standing by; the whole dish is a finishing operation of two or three minutes. Read it as a sauce recipe with oysters folded in at the end.

• The hinge: never let the liaison boilOnce the raw yolks and cream go in, the sauce must not exceed about 180°F/82°C or the yolks curdle and the sauce breaks into threads. Pull the pan off the heat, temper a ladle of hot velouté into the yolk-and-cream mixture, then return it and stir over the barest heat until it coats a spoon.
• Velouté, No. 415A white roux — equal butter and flour cooked without colour — moistened with veal or chicken stock and simmered until it naps. For oysters, a light chicken or fish velouté is closer to the intent than veal. Reducing it with the oyster liquor is what makes the sauce taste of oysters rather than of flour.
• Strain the oyster liquorShucked oysters carry shell grit and bits of shell in their liquor. Pass it through a fine sieve or a coffee filter before it goes into the sauce; there is no later step that will catch it.
• Cooking the oystersThe recipe gives no cooking step for the oysters themselves; it says only to mix them with the sauce. Presumably they are plumped first, as oysters generally are in the neighbouring poulette-style entry — poached in their own liquor just until the edges ruffle, then lifted out. Anything longer and they tighten into rubber. Adding them to the finished sauce off the heat, only to warm through, is the safest reading.
• Lobster butter, No. 580Lobster shells and coral pounded with butter, warmed, then strained; it supplies the pink colour and the shellfish depth. A modern substitute is butter blended with lobster or shrimp shells roasted and simmered, then chilled and lifted off. It is added off the heat so it emulsifies rather than melts to oil.
• QuantitiesNone are given here, as in many of the composed-dish entries in The Epicurean. As a working scale: about a cup of velouté reduced with half a cup of strained oyster liquor, finished with 2 egg yolks beaten into 1/4 cup cream and 2 tablespoons lobster butter, will dress two to three dozen oysters and serve four.
• ServingThis is a hot entrée, not a baked dish. Ranhofer specifies no vessel; comparable fricassees of the period were sent out in a casserole, in vol-au-vent cases or on toast. It does not hold — the liaison thins and the oysters weep — so plate immediately.
• ParsleyChopped parsley, added at the last moment. Left sitting in a warm sauce it loses its colour and freshness.