Salt, pepper, egg(s), ketchup, the soaked bread crumbs, the soup, probably would throw in some better than boullion dissolved. For extra special I lay bacon strips over the top and down the sides of the top and rub chili sauce over it.
Then sometimes, got the idea from a guy I used to know, cut cold slices, lay in skillet, pour Golden Mushroom Soup over all, sprinkle with oregano, maybe add sm amt of water for steam, cover until heated through. I never liked the Golden Mushroom soup for anything but this.
Also like sandwiches, of course or heat up again.