In a frying pan, caramelize onions in olive oil or bacon grease. Add salt and pepper to taste. Add ground beef and cook until browned. Add beans and about 2 pinches of brown sugar, cook until heated through and consistency of a sandwich. Serve on bun with lettuce or shredded cabbage, if desired.

Variations:
If desired, add one or more of the following before you add the ground beef:
1 green pepper, diced
3 stalks celery, diced

If desired, add one or more of the following when you add the beans:
1/2 to 3/4 cup ketchup (to taste)
1/2 cup barbecue sauce
2 tablespoons yellow or brown mustard
Other spices as desired (cayenne pepper, Worcestershire sauce, etc.)