Lobster Thermidor

Preparation

1. Step 1

   Twist the cooked lobster claws and remove them from the body. Crack open the claws with a sharp knife or lobster cracker and remove the meat to a bowl; discard the shells. Using a large, sharp knife, cut each lobster body in half lengthwise. Remove and discard the tomalley, the soft, green substance, and any visible roe, then lift out the tail meat and add it to the bowl. Thoroughly rinse the lobster shells, then set them on a paper towel-lined sheet pan, and pat dry. Chop the lobster meat into ½-inch pieces.

2. Step 2

   Melt the butter in a medium saucepan set over medium-low. Add the shallots and cook, stirring occasionally, until translucent, about 2 minutes. Add the mushrooms and garlic and cook, stirring occasionally and lowering the heat if the shallots begin browning, until the mushrooms have released their liquid, 2 to 3 minutes.

3. Step 3

   Add the flour and cook, stirring constantly, until no white flecks remain, about 30 seconds. While stirring, gradually pour in the fish stock. Stir until incorporated, then add the cream, Cognac and salt, and bring to a simmer over medium heat. Reduce the heat and simmer, stirring often and scraping the bottom of the pan, until the sauce is thick but still pourable, 4 to 6 minutes.

4. Step 4

   Cool for 5 to 10 minutes, until warm to the touch. Add ½ cup of the Parmesan and the egg yolks and mix well until smooth, then stir in the Dijon, tarragon and cayenne. Fold in the chopped lobster meat.

5. Step 5

   Position an oven rack 6 inches from heat and set it to broil. While the oven heats, line a sheet pan with parchment paper or foil and arrange the lobster shells, cut side up, on the pan evenly spaced apart. Spoon the lobster meat mixture into the shells, filling them completely. Sprinkle with the Gruyère and the remaining 2 tablespoons of the Parmesan.

6. Step 6

   Broil, watching carefully and rotating the pan halfway through if necessary, until the cheese is evenly browned, 3 to 5 minutes. Garnish with parsley and serve with lemon wedges on the side.