Classic Coquilles Saint-Jacques: The Ultimate French Scallop Gratin

🌍 Cuisine: French
🏷️ Category: Appetizer / Main Course
⏱️ Prep: 25 minutes
🍳 Cook: 20 minutes
👥 Serves: 4 servings

📝 About This Recipe

Transport your senses to a coastal French bistro with this quintessentially elegant seafood bake. Tender sea scallops are poached in a fragrant white wine aromatics, then nestled in a velvet-smooth Gruyère cream sauce and topped with golden, buttery breadcrumbs. It is a timeless masterpiece that balances the delicate sweetness of the ocean with the sophisticated richness of classic French technique.

🥗 Ingredients

The Scallops & Poaching Liquid

  • 1.5 pounds Sea Scallops (tough side muscle removed, patted dry)
  • 1/2 cup Dry White Wine (such as Sauvignon Blanc or Muscadet)
  • 1 Shallot (finely minced)
  • 2 sprigs Fresh Thyme
  • 1 Bay Leaf

The Mornay Sauce

  • 3 tablespoons Unsalted Butter (divided)
  • 3 tablespoons All-Purpose Flour
  • 1 cup Whole Milk (warmed)
  • 1/2 cup Gruyère Cheese (finely grated)
  • 2 tablespoons Heavy Cream
  • 1/2 teaspoon Kosher Salt (or to taste)
  • 1/4 teaspoon White Pepper (ground)
  • 1 pinch Nutmeg (freshly grated)

Mushrooms & Topping

  • 8 ounces Button Mushrooms (very finely sliced)
  • 1/2 cup Panko Breadcrumbs (for crunch)
  • 2 tablespoons Fresh Parsley (finely chopped)
  • 1 teaspoon Lemon Juice (freshly squeezed)

👨‍🍳 Instructions

  1. 1

    Preheat your oven to 425°F (220°C). If you are using traditional scallop shells, place them on a rimmed baking sheet; otherwise, use four individual shallow ramekins.

  2. 2

    In a medium saucepan, combine the white wine, minced shallots, thyme sprigs, and bay leaf. Bring to a gentle simmer over medium heat.

  3. 3

    Add the scallops to the simmering liquid. Cover and poach for exactly 2 minutes—they should be slightly undercooked as they will finish in the oven. Remove scallops with a slotted spoon and set aside.

  4. 4

    Increase the heat and boil the remaining poaching liquid until it reduces to about 3 tablespoons. Strain through a fine-mesh sieve and reserve this concentrated 'liquor'.

  5. 5

    In a separate skillet, melt 1 tablespoon of butter. Add the mushrooms and a pinch of salt. Sauté until the moisture has evaporated and they are golden brown. Stir in the lemon juice and set aside.

  6. 6

    To make the roux, melt the remaining 2 tablespoons of butter in a clean saucepan over medium-low heat. Whisk in the flour and cook for 1-2 minutes without browning.

  7. 7

    Slowly pour in the warm milk, whisking constantly to prevent lumps. Simmer until thickened, about 3-4 minutes.

  8. 8

    Stir the reserved concentrated poaching liquid and heavy cream into the sauce. Remove from heat and stir in half of the Gruyère cheese, salt, white pepper, and nutmeg until smooth.

  9. 9

    If your scallops are very large, slice them in half horizontally. Gently fold the scallops and sautéed mushrooms into the prepared cream sauce.

  10. 10

    Spoon the mixture evenly into the shells or ramekins. Ensure the scallops are well-distributed.

  11. 11

    In a small bowl, toss the panko breadcrumbs with the parsley and the remaining Gruyère cheese. Sprinkle this mixture generously over the top of each dish.

  12. 12

    Bake for 10-12 minutes until the sauce is bubbling and the topping is a deep golden brown. For an extra-crispy top, broil for the final 60 seconds.

  13. 13

    Remove from the oven and let rest for 2 minutes before serving. Garnish with an extra pinch of parsley if desired.

💡 Chef's Tips

Always use 'Dry Packed' sea scallops; 'Wet' scallops are treated with phosphates that prevent them from searing and release too much water. Do not overcook the scallops during the poaching phase; they should still be translucent in the center. If you don't have scallop shells, use shallow ceramic gratin dishes to ensure the ratio of topping to sauce is perfect. For a richer flavor, you can substitute half of the button mushrooms with chopped chanterelles or oyster mushrooms. Make sure your white wine is one you would actually drink; the reduction concentrates the flavor significantly.

🍽️ Serving Suggestions

Serve with a crisp, chilled glass of Chablis or Sancerre to cut through the richness of the cream sauce. Pair with a simple side of steamed haricots verts (French green beans) tossed in lemon butter. Provide crusty pieces of a fresh French baguette to soak up every last drop of the Mornay sauce. A light arugula salad with a sharp champagne vinaigrette provides a refreshing acidic contrast to the dish.