INGREDIENTS
2 cups
leftover shredded pot roast
8
slices sturdy bread
3 tbsp
butter, plus more for the bread
2
medium onions, thinly sliced
Salt and pepper
4
slices Provolone cheese
4
slices cheddar cheese
1/2 cup
mayonnaise
3 tbsp
steak sauce
1/8 tsp
pepper