Difficulty! [usr 3]
First, peel, seed and cut the cucumber into cubes, then put them to soak in salt for about an hour. Rinse them. Peel the tomatoes, shell them, cut them into cubes of the same size. Also prune the mushrooms.
Throw the coarse salt into a liter of boiling water over high heat; cook all the diced vegetables "al dente"; refresh them under running water.
Melt 2 knobs of butter in a sauté pan over high heat, add the vegetables, lower the heat and cover. Cook very gently for about 15 minutes. Add the vermouth, cook for about 10 minutes; add the whipping cream, check the seasoning; finish with the chopped chervil.
Mix the crab with the vegetables.
In a buttered gratin dish, spread a layer of lasagna, then a layer of crab stuffing; repeat the operation until all the ingredients are used up; add the veal juice and thyme; bake for 25 minutes in a medium preheated oven (thermostat 7).
At the last moment, add the two knobs of butter.
Serve as is.
