- 1-1/2 lb ground beef
- 4 sweet onion slices (1/2")
- Vegetable oil
- 8 slices Swiss process cheese food
- 1/4 cup mayonnaise
- 1 Tbsp Dijon-style mustard
- 4 crusty rolls, split, toasted
- Romaine lettuce, tomato slices
- Lightly shape ground beef into four 3/4" thick patties. Brush onion with oil.
- Place patties in center of grid over medium, ash-covered coals. Place onion around patties. Grill, uncovered, 13 to 15 minutes to medium (160°F) doneness, until patties are not pink in center and juices show no pink color and onions are tender, turning occasionally. Season with salt and pepper. About 1 minute before patties are done, top each with 2 cheese slices.
- Mix mayonnaise and mustard; spread on roll tops. Serve burgers and onion in rolls with lettuce and tomato.