Combine beer and steak sauce in 1-cup glass measure. Cover and microwave on high 1 to 1-1/2 minutes or until bubbly. Lightly shape ground beef into four 3/4-inch thick patties. Place patties in center of grill over medium heat; arrange onion around patties. Grill, uncovered, 13 to 15 minutes to medium (160°F) doneness, until patties are not pink in center and juices show no pink color and onions are tender, turning occasionally. Season with salt after turning. About 2 minutes before patties are done, brush generously with sauce; top with cheese. Serve burgers and onions in rolls with lettuce and sauce. Makes 4 servings.