Prep: 1. Light a grill or preheat a grill pan to moderately high heat. 2. Thinly slice onions and toss with 2 tablespoons of olive oil. 3. Slice brie. 4. Whisk mayonnaise with lemon juice. Gradually add remaining olive oil; season with salt and pepper. 5. Form ground meat into eight patties. Season generously with salt and pepper and brush with olive oil. Make: 1. In a separate pan, cook bacon over moderately high heat until crisp. Drain on paper towels and break each strip in half. 2. Grill onions and burgers until well-browned on the bottom, 5 minutes. 3. Flip both onions and burgers and mound brie on top of each burger. Grill for 4 minutes longer, until cheese is slightly melted and burgers are medium-rare. Cook onions until soft and golden brown. 4. Spread lemon mayonnaise on buns and place burgers, bacon and onions on top. Serve immediately.
We also love to add tomatoes and lettuce to these. If you prefer to grill these, just preheat the grill before beginning prep, then when the grill is hot grill the burgers for 2 minutes on each side, then move them to a lower-heat area of the grill. Cook a total of another 2-3 minutes for medium-rare burgers, 3-4 minutes for medium, or 5-6 minutes for well-done burgers.