Lobster thermidor gratinéed in its shell

Bring a pot of water to a rolling boil. Kill the lobster first by plunging the knife point into the head between the eyes, pushing down then upward.

Boil the lobster (about 1.5 lb) 10 to 12 minutes, until bright red and the feelers pull easily from their sockets.

Drain the lobster by piercing the head; remove the rubber bands.

Slice the mushrooms; stew them gently in a covered saucepan with 1 tbsp butter, lemon juice and salt.

Add wine and water (about three parts to one) with salt and pepper; boil down to around 400 ml.

Strain the mushroom juices into another pan; keep the mushrooms aside off the heat.

Cook 4 tbsp butter and 1.5 to 2 tbsp flour slowly together for 2 minutes.

Whisk in the reduced mushroom liquid, boil 1 minute, take off the heat and film the top with about a tablespoon of cream.

Split the lobster in half with scissors; discard the sand sack and intestinal tube; set aside the coral and green matter.

Push the green matter through a fine sieve into a mixing bowl; add the egg yolk, 1/2 tbsp Dijon mustard, about 100 ml cream and a pinch of cayenne.

Add the sauce drop by drop to the yolk mixture, then pass through a fine sieve.

Return to the heat and bring to a boil, adding 4 tbsp heavy cream, until thick enough to coat a spoon. Season with salt and pepper and film the top with another tablespoon of cream.

The butter separated from the sauce; another tablespoon of cream and a little more were added to try to bring it back.

Remove the meat from the tail, claws and legs and cut into small pieces.

Melt butter in a frying pan over medium heat until it foams; add the lobster meat and stir slowly about 5 minutes until rosy.

Add brandy, shake the pan and boil 1 to 2 minutes until the liquid reduces by half.

Fold in the cooked mushrooms and two thirds of the sauce.

Rinse the split lobster shells, heap the lobster mixture into them, and cover with the remaining sauce.

Top with Parmesan; bake on the top rack of a 425F oven 10 to 15 minutes until golden brown on top.

Finish with greenery and lemon on top.