1. Place 2 cheese slices each on 8 bread slices. Top each with 1/4 cup Pickled Red Onion, 1/2 cup Pulled Beef Short Ribs, and 2 more cheese slices. Top with remaining bread slices.
2. Brush top slices of bread with 1 tablespoon butter, and invert onto preheated grill or nonstick skillet. Brush other sides of sandwiches with remaining 1 tablespoon butter; cook over medium heat until golden. Turn sandwiches, and brown other sides. Cut diagonally with a serrated knife, and serve immediately.