Stuffed Burgers with Carmelized Onions & Swiss Cheese

Submitted by HBeachlady

2 pounds Lean ground beef
1/4 teaspoon salt
1/2 teaspoon freshly ground pepper
3 tablespoons Creole mustard
1 large onion, thinly sliced
1 teaspoon sugar
1/2 teaspoon olive oil
4 (1- to 11/2-ounce) Swiss cheese slices
Vegetable cooking spray
6-8 whole grain buns, split and toasted
6-8 green or red leaf lettuce pieces
6-8 tomato slices
Ketchup, light mayonnaise (optional)

1. Combine lean ground beef and next 3 ingredients; (shape into 12 equal-size patties for 6 servings or 16 patties for 8 servings); cover and chill.
2. Cook onions and sugar in hot oil over medium-low heat 30 minutes, or until caramel-colored, stirring occasionally. Cool 10 minutes.
3. Spoon onions evenly over half of the patties. Top evenly with cheese slices, tearing cheese slices as needed to fit patties. Cover with remaining patties, pressing edges to seal.
4. Coat grill rack with cooking spray. Grill, covered with grill lid, over medium-high heat (350 to 400) 5 to 7 minutes on each side or to desired degree of doneness.
5. Arrange stuffed patties over bun bottoms, top with lettuce, tomato, and if desired, ketchup and mayonnaise.

Stove Top Directions 1. Place patties in a large skillet over medium-high heat; cook 8 to 10 minutes on each side or until done.
Broiler Directions 1. Broil 51/2 inches from heat (with electric oven door partially open) 8 to 10 minutes on each side or until beef is no longer pink.

Makes 6-8 servings