Ingredients

• ³⁄₄ cup dry vermouth
• 1 bay leaf
• 1 large shallot, quartered
• Kosher salt and freshly ground white pepper, to taste
• 18 medium sea scallops
• 8 tbsp. unsalted butter
• 16 oz. button mushrooms, sliced 1/4″ thick
• 3 tbsp. flour
• ¹⁄₂ cup heavy cream
• ¹⁄₂ tsp. fresh lemon juice
• 1 ¹⁄₂ cups grated Gruyère

Instructions

1. Boil vermouth, bay leaf, shallot, salt, white pepper, and ¹⁄₂ cup water in a 4-qt. saucepan over medium heat. Add scallops; cook until just tender, 1–2 minutes. Using a slotted spoon, divide scallops between six cleaned scallop shells or shallow gratin dishes. Simmer cooking liquid until reduced to ³⁄₄ cup, 5–7 minutes. Strain liquid; set aside.
2. Wipe pan clean; melt 4 tbsp. butter over medium-high heat. Cook mushrooms until soft, 5–7 minutes. Divide mushrooms between scallop shells. Wipe pan clean; melt remaining butter over medium-high heat. Stir in flour; cook 2 minutes. Add reserved cooking liquid, the cream, lemon juice, salt, and white pepper; bring to a boil. Cook until sauce is slightly thick, about 6 minutes.
3. Heat oven broiler. Spoon sauce over scallops and top with Gruyère; broil until cheese is melted and golden, 2–3 minutes.