• Mix together ground turkey, bread crumbs, egg, 2 tbsp balsamic glaze, grated onion, mustard, Worcestershire sauce, garlic, salt, thyme and pepper. Divide into 4 portions; shape into 1/2-inch thick patties.
• Heat grill to medium heat; grease grate well. Grill for 6 to 8 minutes per side or until meat is cooked through and instant-read thermometer reads 160°F when inserted into center of burger. Top each burger with cheese slice; grill for about 1 minute or until cheese starts to melt.
• Meanwhile, brush onion rounds with olive oil; grill for about 2 minutes per side or until lightly charred and tender. Grill buns for 30 to 60 seconds or until lightly toasted. Assemble cheeseburgers in buns with lettuce, tomato, grilled onions and drizzle of remaining balsamic glaze.

Tip: Top burger with bacon if desired.