Seafood Stuffed Shells Recipe

Name: Seafood-Stuffed Shells Recipe
Ingredients: Kosher salt; 6 ounces dry jumbo pasta shells (about 25 shells; 170g) (see note); Extra-virgin olive oil, for drizzling and greasing the baking dish; 8 ounces (225g) peeled and deveined shrimp; 1 pound (450g) lump crabmeat, picked over for shells; 8 ounces (225g) dry-packed sea scallops, cut into small pieces (see note); 2 tablespoons (30ml) Dijon mustard; 1/2 cup (120ml) mayonnaise; Dash of Old Bay seasoning; 1 medium shallot (about 2 ounces; 60g), minced; Small handful minced flat-leaf parsley, plus more for garnish; Freshly ground black pepper; 3 1/2 tablespoons (50g) unsalted butter, divided; 1 1/2 tablespoons (12g) all-purpose flour; 1 1/2 cups (360ml) milk; 1 bay leaf; 1 cup panko bread crumbs (about 3 1/2 ounces; 100g)