For a perfect London broil, proper slicing is as important as the cooking technique. This especially thin cut of steak cooks quickly, and Paula Deen's recipe employs an oven to roast a perfect London broil in minutes.
Preheat the oven broiler, and line a rimmed baking sheet with foil. Season a 3 pound London broil with salt and pepper. In a large, non-reactive skillet over low heat, combine 1/3 cup balsamic vinegar, 1 tablespoon packed brown sugar, 1 smashed and peeled garlic clove and 1 bay leaf. Simmer for approximately 5 minutes until the liquid has reduced by half and is syrupy. Remove the garlic and bay leaf.
Place the meat on the baking sheet, and slowly pour the glaze over the top. Broil the meat 4 inches from the heat until it reaches the desired level of doneness. For medium-rare, cook about 4 minutes on each. Cooking time varies greatly depending on steak thickness.
To prevent burning, keep the oven door cracked open during broiling. Remove the meat from the broiler to a cutting board, and let it rest for at least 5 minutes. The steak continues to cook while resting. Thinly slice the meat against the grain before transferring it to a serving platter.