Preheat oven to 425°; Spray 8 (4-in.-round) ramekins with nonstick spray; place in a rimmed baking pan. Pat scallops and salmon dry with paper towels; set aside.

Melt ¼ cup butter in a large, deep nonstick skillet over medium-low heat. Add scallops and salmon; cook for 3 to 4 minutes or until scallops begin to brown and salmon begins to flake, turning occasionally. Add frozen mixed vegetables, red onion, smoked paprika and concentrated shrimp & crab boil; cook for 2 to 3 minutes. Stir in ¾ cup water, cream of mushroom soup, potatoes and 2 tsp. potato seasoning packet; cook for 3 to 4 minutes more or until heated. Divide mixture evenly into ramekins; set aside.

For biscuit topping, set aside biscuit seasoning packet. Stir together biscuit mix, remaining ¾ cup water and cheese until dough forms. Do not overmix. Using 2-in. scoop, place a dough mound on top of seafood mixture in each ramekin. Bake for 14 to 16 minutes or until biscuits are golden brown and seafood reaches 145°.

Microwave remaining 2 Tbsp. butter in a small microwave-safe bowl until melted. Stir in reserved biscuit seasoning until combined.

Lightly brush butter mixture on each biscuit topper. Let stand for 5 minutes before serving.