Prepare your mac and cheese (or reheat if pre-prepared) and set aside.
In a medium microwave-safe bowl, reheat the shredded chicken, pork or beef. Add the barbecue sauce and mix well. Set aside.
Preheat a griddle or medium skillet to medium heat.
Brush melted butter onto 2 slices of sourdough bread. Place 1 slice on the griddle, buttered side down. Add 2 slices of Cooper Cheese. On top of the cheese, spoon a layer of prepared barbecue meat. Dollop a layer of prepared mac and cheese on top of barbecue meat and spread to edges of the bread. Drizzle with extra barbecue sauce. Cap with the second slice of sourdough bread, buttered side up.
Toast until bread is golden brown, or about 4 minutes. Carefully flip sandwich and grill the other side until toasted.
Repeat for all 4 sandwiches (or prepare at the same time as space allows). Serve and enjoy!