- 1 1/2 pounds ground beef
- 1 large sweet onion, cut crosswise into 1/2-inch thick slices
- Vegetable oil
- Salt and pepper
- 4 hamburger buns, split, toasted
- Lettuce leaves
- Tomato slices
- Lightly shape ground beef into four 3/4-inch thick patties. Brush onion slices with oil.
- Place patties and onion slices on grid over medium, ash-covered coals. Grill, covered, 11 to 15 minutes (over medium heat on preheated gas grill, 13 to 14 minutes) until instant-read thermometer inserted horizontally into center registers 160 degrees F, turning occasionally. Grill onions, 10 to 12 minutes or until tender, brushing with oil and turning occasionally.
- Season burgers and onions with salt and pepper as desired.
- Line bottom of each bun with lettuce. Place burgers on top of lettuce. Top with tomatoes and grilled onions. Close bun.