Creamy Seafood-Stuffed Shells with Golden Bread Crumb Topping

Method

1. Preheat the oven to 325°F and set a rack in the middle. Bring a large pot of salted water to a boil and cook the shells according to the package directions for baked shells (if none are given, cook them 3 minutes less than the recommended time). Use a slotted spoon or spider to transfer the shells to a bowl of cold water to cool, then drain. Reserve the pasta water. Lightly drizzle the shells with olive oil and toss to coat; set aside.
2. Fill a large bowl with ice water. Poach the shrimp in the same pot of pasta water until just cooked through, about 1 to 2 minutes. Drain, plunge into the ice bath to cool, then drain again. Chop the shrimp into small pieces.
3. In a mixing bowl, combine the crabmeat, chopped shrimp, scallops, Dijon mustard, mayonnaise, Old Bay, minced shallot, and parsley. Mix well and season with salt and pepper.
4. In a small saucepan, melt 1½ tablespoons (20g) of the butter over medium-high heat without letting it brown. Whisk in the flour and cook for about 1 minute, stirring constantly, until the raw flour smell disappears. Gradually pour in the milk, whisking continuously to keep the sauce smooth. Add the bay leaf.
5. Bring the sauce to a simmer, stirring often, and cook until it thickens enough to coat the back of a spoon, about 3 minutes. Season with salt and pepper. Remove the bay leaf and set the béchamel aside.
6. Lightly grease a 9x13-inch baking dish with olive oil. Spread ½ cup (120ml) of the béchamel evenly over the bottom. Fill each cooked shell with a generous spoonful of the seafood mixture and place it in the dish, opening side up. Repeat until the dish is full (you should fit about 18 shells).
7. Spoon the remaining béchamel (about 1 cup/240ml) over the stuffed shells. Melt the remaining 2 tablespoons (30g) of butter and toss it with the panko bread crumbs in a small bowl; season with salt. Sprinkle the bread crumb mixture evenly over the shells.
8. Bake the shells until heated through, about 25 minutes. Switch the oven to broil and, watching carefully to prevent burning, broil until the bread crumbs are golden brown, rotating the dish occasionally for even browning. Garnish with minced parsley and serve.