Ingredients:

For the 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

For the 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

Methods:

Prepare grill or broiler.

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.

Prepare Burger:
Heat pan coated with cooking spray over medium-high heat. Add bell pepper and celery; sauté 3 minutes or until tender.Combine the bell pepper mixture, crackers, 1/4 cup ketchup, thyme, 1/4 teaspoon salt,beef,and egg in a large bowl. Shape into patties using Burger Mate. 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. Place 1 patty on each of 6 bread slices. Top each patty with 1/4 cup onion mixture and 1 bread slice.