4 hamburger buns
1 tablespoon olive oilInstructions
In a large skillet over medium heat, cook onions in 4 teaspoons olive oil until golden brown. Add 1/4 teaspoon salt and 1/4 teaspoon pepper; cover and keep warm.
In a large bowl, combine Worcestershire sauce, 1/2 teaspoon pepper, and ground beef; mix well. Divide into eight portions and shape each into 4-inch patties. Divide cheese among four of the patties. Top with remaining patties, pressing down gently and sealing the edges well. Grill patties, uncovered, directly over medium coals for 14 to 18 minutes; turn once halfway through grilling.
Brush buns with 1 tablespoon olive oil; grill until toasted. Place patties on toasted buns and top with onion mixture.