1 pound ground beef
1 medium onion, chopped
1 can condensed cheddar cheese soup
1 tbsp. prepared mustard
1/8 tsp. pepper
6 hamburger buns, split (may toast)

In medium skillet cook beef and onion until beef is browned, stirring to separate meat. Drain off fat. Add soup, mustard and pepper. Reduce heat to low and simmer. Divide meat mixture among buns. Serve.