1. Preheat the oven to 350°F (180°C).
2. Melt the butter and sauté the finely chopped shallot for 2 minutes, then add the flour. Stir constantly, then pour in the white wine and broth.
3. Let simmer over medium heat, stirring to thicken the cream.
4. Once the consistency of béchamel is obtained, season with salt and pepper.
5. Clean and slice the mushrooms, then sauté them in a little oil.
6. Sear the scallops in a pan for a few minutes.
7. Add the cream, mushrooms, and scallops to the sauce, then distribute the mixture into scallop shells.
8. Sprinkle with breadcrumbs and bake for 10 minutes. Serve hot with a green salad.