To broil patties, place on broiler pan; broil 4 to 6 inches from heat using times above as a guide, turning once. Place buns, cut side up, on broiler pan; broil 1 to 2 minutes.
Sweet onions, available during spring and summer, have a mild flavor. Vidalia, Walla Walla and Maui are three varieties of sweet onions that are very juicy.
Serve these burgers on any flavorful bun such as sourdough or whole wheat.
For extra blue cheese flavor, spread toasted buns with your favorite blue cheese dressing before assembling the burgers.