My mom made many varieties of hotdish only in Ohio and Indiana we always just called them casseroles. They are easy meals to mix and match ingredients that you have on hand to make a complete meal in one baking dish.
She had a poster on the wall of our pantry with several columns across. You were supposed to pick an ingredient from each column to make a casserole.
The ingredients in the first column were meats or proteins like ground beef, turkey, tuna, chicken, etc and the second column ingredients were starches like potatoes, spaghetti, beans, macaroni, rice, tater tots, hash browns, French fries. Another column featured vegetable choices, fresh frozen or canned corn, lima beans, broccoli , carrots,
tomatoes, green beans, etc. Then there was a column for condensed soup: cream of mushroom, cream of chicken, golden mushroom, cream of celery, etc. A column for all different types of cheese to select from. A column for optional ingredients like onions, peppers, mushrooms, etc. Then the last column was for toppings like crushed potato chips, bread crumbs, French fried onions, etc.
As kids we were fascinated with that poster, at the bottom it had the total number of possible combinations which was a huge number. When I took algebra in 8th grade I knew how to calculate combinations and so I really enjoyed that poster.