Servings: 8
Ingredients  : 

2 tablespoons balsamic vinegar
2 pounds extra-lean ground beef
1/2 teaspoon freshly ground black pepper
16 medium slices sweet onions
cooking spray
1/2 teaspoon salt
16 (1-ounce) slices rye bread
6 tablespoons dijon-mayonnaise blend
2 cups shredded reduced-fat jarlsberg
cheese

Directions  : 

step 1 Organize onion slices on a plate and drizzle vinegar over top. Divide meat into 4 similar portions, shaping each into a 1/2-inch thick patty. Period patties with sodium and pepper.

Step 2 Heat a sizable barbeque grill pan over medium heat. Coat the pan with food preparation spray and add onion. Cover and cook for six minutes, flipping midway. Remove from skillet, cover, and keep warm.

Step 3 Heat the barbeque grill pan over medium-high heat. Coat with more cooking squirt and add patties. Cook until forget about pink in the centers, about 3 minutes per aspect. An instant-read thermometer inserted into the center should read at least one hundred sixty degrees F (71 degrees C).

Remove patties to a plate, drain and discard any oil, and wipe the pan clean with a paper bath towel.

Step 4 Spread Dijon-mayonnaise blend evenly over all bread pieces. Layer 4 of the slices with 2 tablespoons Jarlsberg cheese, 1 meat patty, 2 red onion slices, and 2 tablespoons Jarlsberg. Place remaining bread pieces mustardside up on the top of the sandwiches.

Step 5 High temperature the grill skillet over medium-high temperature and coat with cooking spray. Add sandwiches to the pan and place a cast iron or other heavy skillet at the top, pressing gently to trim sandwiches. Cook until bread is done, about 3 minutes per side, departing the skillet on top as they cook.