Blue-poached trout with lemon butter

Peel the carrot, celeriac and onion. Trim the root end and damaged leaves from the leek, then wash it thoroughly. Cut the vegetables into large pieces. Put them in a fish kettle long enough for the trout with the water, vinegar, 15 g salt, peppercorns and juniper berries. Bring to the boil and cook for 20 min.

Gently rinse the gutted trout under cold water. Do not scale or dry them, to preserve the thin slime layer on the skin. Reduce the heat and lower them into the hot court bouillon without letting it boil. The liquid should cover the fish. Poach uncovered for 15–20 min, until the flesh is opaque and comes away easily from the bone.

While the fish poaches, wash and dry the lemon. Finely grate the zest without the white pith, then slice the lemon. Melt the butter in a small saucepan until foaming. Add the zest and 1 g salt, then remove from the heat. Snip the cress at its base, rinse and drain. Carefully lift out the trout, let them drain and spoon the lemon butter over them. Add the cress and lemon slices.