Preheat the oven to 350°F (175°C)
Drain and rinse canned beans
In a mixing bowl, combine beans, cream of mushroom soup, milk, and black pepper
Stir in cooked onions or sautéed onions if desired
Transfer the mixture to a greased casserole dish
Top with fried onions or breadcrumbs
Bake for 25 to 30 minutes
Remove from the oven and let it rest for a few minutes before serving