2 tsp. olive oil
1 medium sweet onion, sliced and separated into rings
2 (8 oz.) packages pre-sliced mushrooms
1/2 tsp. salt
2 tsp. balsamic vinegar
1 1/2 Tbls. paprika
1/2 tsp. salt
1/2 tsp. dried thyme
1/4 tsp. ground red pepper
1/4 tsp. freshly ground black pepper
1 lb. ground round
2 English muffins, split and toasted

Preheat grill.

Heat oil in a large nonstick skillet over medium-high heat. Add onion, and cook for 5 minutes or until golden. Add mushrooms and salt; cook 5 minutes, stirring constantly. Add vinegar; remove mixture from pan. Set aside.

Combine the paprika and the next 4 ingredients (paprika through black pepper). Divide the ground round into 4 equal portions, shaping each into a 1/2-inch-thick patty. Coat patties with spice mixture. Grill patties 4 minutes on each side or until done. Place burgers on muffin halves, and top each burger with 1/4 cup onion mixture.

Yield: 4 servings.