Cook pasta shells according to package directions.
Meanwhile, in a small skillet over medium heat, cook scallops in butter 1-2 minutes or until opaque. Transfer to a large bowl.
Preheat oven to 350°. Place one egg and half the cottage cheese, ricotta, nutmeg and pepper in a blender; cover and process until smooth. Add to scallops. Repeat with remaining egg, cottage cheese, ricotta, nutmeg and pepper. Add to scallops. Stir in crab and shrimp.
Drain shells and rinse in cold water. Stuff with seafood mixture. Place in a greased 13x9-in. baking dish. Top with Alfredo sauce.