Patty Melts with Grilled Onions

Ingredients

• 1 tablespoon balsamic vinegar 
• 0.3 teaspoon pepper black freshly ground
• 1 pound extralean ground beef 
• 4 ounces jarlsberg cheese shredded reduced-fat
• 3 tablespoons creamy mustard blend (such as Dijonnaise)
• 1 ounce cocktail rye bread 
• 0.3 teaspoon salt 
• 1 inch vidalia sweet

Equipment

• frying pan
• grill pan

Directions

1. Arrange onion slices on a plate.
2. Drizzle vinegar over onion slices.
3. Heat a large grill pan over medium heat. Coat pan with cooking spray.
4. Add onion to pan; cover and cook 3 minutes on each side.
5. Remove from pan; cover and keep warm.
6. Heat pan over medium-high heat. Coat pan with cooking spray. Divide beef into 4 equal portions, shaping each into a 1/2-inch-thick patty.
7. Sprinkle patties evenly with salt and pepper.
8. Add patties to pan; cook 3 minutes on each side or until done.
9. Spread about 1 teaspoon mustard blend over 4 bread slices; layer each slice with 2 tablespoons cheese, 1 patty, 2 onion slices, and 2 tablespoons cheese.
10. Spread about 1 teaspoon mustard blend over remaining bread slices; place, mustard side down, on top of sandwiches.
11. Heat pan over medium heat. Coat pan with cooking spray.
12. Add sandwiches to pan.
13. Place a cast-iron or other heavy skillet on top of sandwiches; press gently to flatten. Cook 3 minutes on each side or until bread is toasted (leave cast-iron skillet on sandwiches while they cook).