For the sandwiches:
2-3 cups leftover shredded pot roast
8 slices sturdy bread
3 tablespoons butter, plus more for the bread
2 medium onions, thinly sliced
Salt and pepper to taste
4 slices Provolone cheese
4 slices cheddar cheese
For the sauce: (can leave this out)
1/2 cup mayonnaise
3 tablespoons steak sauce
1/8 teaspoon pepper
1 - Re-heat the pot roast in the microwave. Butter one side of all 8 slices of bread.
2 - Melt 3 tablespoons of butter in a large skillet. Add onions and cook over medium heat, stirring frequently, until onions are soft and golden brown.
3 - Season with salt and pepper and remove from heat.
4 - Combine the sauce ingredients in a medium bowl.
5 - Heat a griddle or skillet over medium-high heat. Spread a layer of the sauce on the unbuttered side of 4 slices of bread. Top with a piece of cheddar cheese.
6 - Top each slice of cheddar with about 1/2 cup of pot roast, a generous portion of onions, and the slice of Provolone cheese. Top with the remaining slice of bread, buttered side out.
7 - Grill, flipping once, until both sides are browned and crispy.
8 - Serve patty melts with the remaining sauce, for dipping.