Ingredients

• 2 tablespoons unsalted butter
• ½ cup diced shallots
• ½ pound white button mushrooms, sliced
• salt and freshly ground black pepper to taste
• 1 cup white wine
• 1 pound sea scallops
• ½ cup heavy whipping cream
• 1 egg yolk
• 2 teaspoons minced fresh tarragon
• 1 teaspoon lemon zest
• 1 pinch cayenne pepper, or to taste
• 4 large oven-safe scallop shells
• ¼ cup shredded gruyere cheese
• 1 pinch paprika
• 8 fresh tarragon leaves