Crayfish Sauce

• 18 oz (500 g) crayfish (or small langoustines, or at a Pinch

Blanch the fish in boiling water for 2 or 3 minutes. Separate the tail meat intact and set aside for use as a garnish with a mousse or a poached fish, as desired.

Grind the shells in the liquidiser and cook in butter, adding the Cognac and the fish stock. Simmer for 10 minutes or so.

Cream the flour and butter together with your fingers and stir into the stock to thicken. Check