Crayfish in Light Butter Sauce (Écrevisses à la nage)

Separate crayfish tails from heads, reserving six whole crayfish garniture.

Bring the Court Bouillon [2] to a boil and add the crayfish tails. Cook for 2 minutes, or until tails turn red. Remove from liquid and reserve. Cook the whole crayfish for 3 to 4 minutes, or until bright red. Reserve.

Peel the onions and carrots. Cut them into very thin slices. Cook separately in 1 cup Court Bouillon [2] until just tender. Reserve.

To make the nage: Reduce 1 cup Court Bouillon [2] until only 1/2 cup remains. Whisk in the butter, one piece at a time. Add salt, pepper, and lemon juice to taste.

Peel crayfish tails and place nine tails in each of six warm soup plates. Arrange a few slices of the carrots and onions on each plate. Pour nage over all. Sprinkle with minced tarragon and garnish each plate with a whole crayfish.