Meat Loaf Burgers with Caramelized Onions

Ingredients

• Onions:
• 1 teaspoon olive oil
• 4 1/2 cups vertically sliced red onion (about 2 medium onions)
• 1/4 teaspoon salt
• 1 tablespoon sugar
• 2 tablespoons balsamic vinegar
• Burgers:
• Cooking spray
• 1 cup finely chopped green bell pepper
• 1 cup finely chopped celery
• 1 cup crushed whole wheat crackers (about 20 crackers)
• 1/3 cup ketchup, divided
• 1/2 teaspoon dried thyme
• 1/4 teaspoon salt
• 1 pound ground sirloin
• 1 large egg
• 12 (1 1/4-ounce) slices rye bread, toasted

Preparation

1. Prepare grill or broiler.
2. To prepare onions, heat olive oil in a large nonstick skillet over medium-high heat. Add onion and 1/4 teaspoon salt; sauté 12 minutes or until golden brown. Stir in sugar and vinegar; cook 30 seconds. Remove from pan.
3. To prepare burgers, heat pan coated with cooking spray over medium-high heat. Add bell pepper and celery; sauté 3 minutes or until tender.
4. Combine the bell pepper mixture, crackers, 1/4 cup ketchup, thyme, 1/4 teaspoon salt, beef, and egg in a large bowl. Divide mixture into 6 equal portions, shaping each into a 1/2-inch-thick patty.
5. Place patties on a grill rack or broiler pan coated with cooking spray; cook 5 minutes. Carefully turn patties over; brush with remaining ketchup. Cook 5 minutes or until done.
6. Place 1 patty on each of 6 bread slices. Top each patty with 1/4 cup onion mixture and 1 bread slice.