I call them "crusty bun sandwiches" because that's what my mom called them, although she didn't put as much stuff on hers as I put on mine.
There's a particular kind of round bun (or roll, depending on where you live) you can get that has a medium-hard crust and the inside is soft and chewy. Saw one in half with a serrated knife. Spread butter on both halves. On the bottom half, stack a slice of four or five different kinds of deli meat, like roast beef, ham, pastrami, salami, bologna, corned beef, etc., putting some yellow mustard between two of the slices. Add a slice of medium cheddar cheese, a slice of onion, a slice of tomato, a shake of salt and ground pepper, some lettuce, and put the top on. Eat with a kosher deli pickle.
My wife says that these are her favorite. She calls me the King of Sandwiches.
Man, now I'm all hungry!