Inside-Out Cheeseburgers

Source: Eating Well

Ingredients:
1/4 cup shredded Cheddar cheese
1/4 cup shredded Gruyere cheese (i omitted this and doubled the cheddar)
1 pound 90% or 93% -lean ground beef
1 tablespoon Worcestershire sauce
1 1/2 teaspoons paprika
1/4 teaspoon freshly ground pepper

Directions:
1. Preheat grill to medium-high or preheat the broiler.
2. Combine Cheddar and Gruyere in a small bowl.
3. Gently mix beef, Worcestershire, paprika and pepper in a large bowl, preferably with your hands, without overworking. Shape into 8 thin, 4-inch-wide patties. Mound 2 tablespoons of the cheese mixture on each of 4 patties, leaving a 1/2-inch border. Cover each with one of the remaining patties. Crimp and seal the edges closed.
4. To grill: Lightly oil the grill rack. Grill the stuffed patties over medium-high heat, about 4 minutes per side for medium-well. (Be sure not to press the burgers as they cook or they'll split open and the cheese will ooze out.) To broil: Cover a broiler pan with foil and coat with cooking spray. Broil the stuffed patties in the upper third of the oven, about 4 minutes per side for medium-well. In either case, let the burgers stand for 5 minutes before serving.
(I used a grill pan and the broiler. I grilled the burgers on each side for a few minutes until the outside was browned...then I put them in the broiler for 2 min on each side to cook them all the way thru.)
I topped mine with tomatoes, avocados, ketchup, and fresh ground pepper on wheat buns.