In a large skillet over medium heat, cook bacon until crisp. Remove from pan and crumble. Add onion to same skillet, season with salt and pepper and cook until golden brown. Add beer and simmer until it evaporates. In a bowl, mix together bacon, onion, beef, salt and pepper. Form into 4 burger patties about 3 inches in diameter and 1 inch thick. Preheat a grill and oil grill grate well. Grill burgers about 3 minutes on each side for rare, 4 minutes for medium rare. Top with cheese in the last minute of cooking. (Or pan-fry burgers in oil or bacon fat over medium heat about 3 minutes on each side for rare, 4 minutes for medium rare, topping with cheese in the last few minutes of cooking.) Place each burger on the bottom half of a bun and top with mustard and lettuce. Close with top half of bun.
Recipe courtesy of the California Milk Advisory Board
