Can you help me create a dish with ANY of these ingredients?? It's leftover night, but I want something new

This is so simple but my mom used to do this and I would beg for it. You take that left over roast and veggies - slice or pull apart the roast and place it in a cerole dish to fit. Place the onion and veggies on the top and if you have any gravy, put that on top of it all. Grate cheese and place a good bit on top of all of that. Place in 350 degree oven until cheese melts and it gets bubbly. Oh my gosh is it good. Maybe use some green beans and corn as a side.