1. Heat broiler. Place rolls, cut side up, on baking sheet and set aside.
2. Using a fork, roughly shred or mash burgundy pork from leftover Burgundy Pork Over Mashed Potatoes recipe. Place in microwave-safe container; cover and microwave on (100% power) for 2 to 3 minutes until heated.
3. Lightly toast rolls under broiler, about 1 minute; set tops of rolls aside. Spoon equal amounts of burgundy pork on each “bottom” roll. Sprinkle with green onions and top each with 2 slices of cheese.
4. Place under broiler until cheese is bubbly and beginning to brown. Place tops on sandwiches to serve.