Caisses de Laitances à la Nantua

Caisses de Laitances à la Nantua (pleated cases of poached fish milt with crayfish sauce) teaches a severe little lesson: when a dish bears a sauce's name, that sauce carries the whole argument. The one true thing to know before touching a pan is that Sauce Nantua must taste unmistakably of crayfish butter. If it tastes merely of cream, the dish has lost its name.

The original entry assumed a saucier with the finished sauce ready, the house's sauce foundations always within reach, cooked crayfish waiting, and a cupboard of tiny pleated porcelain cases. Your home equivalent is four fluted ramekins, a separately prepared Sauce Nantua warmed gently, and exactly eight tails. A salamander has no work here because the cases are filled, not gratinéed. The brigade's separate station work is scaffolding and may happen ahead; the careful poach, two tails in every case, the sauce, and the fine truffle crown are the dish and must stay. Only the vessel and scale change. Four guests need four cases, not a service tray. One cook, one stove, one evening.

Finished correctly, each caisse is generous rather than fussy: tender ivory slices beneath a gleaming coral-ivory sauce, with sweet crayfish and the dark perfume of truffle at the center. Before you begin, remember the step that decides it: warm the Sauce Nantua gently enough that its crayfish butter stays in the sauce, not as orange beads on top.