Preheat grill to 400°F.
Place beef, Worcestershire sauce, garlic salt, and pepper in a bowl; mix well. Portion into eight even units. Shape each portion into a thin round patty that’s slightly larger than the cheese slice.
Fold cheese slices in half twice so you have a little stack of quartered cheese slices. Place a folded cheese stack on 4 the patties, covering cheese with remaining 4 patties.
Tightly crimp the edges of the patties together to form a tight seal.
Preheat a cast-iron skillet or heavy-bottomed pan to medium heat (or use your grill), and cook burgers 3 to 4 minutes on first side. Note: burgers may puff up due to steam from melting cheese.
Flip burgers. Using a toothpick, prick the tops of the burgers to allow for steam to escape. Allow burgers to cook 3 to 4 minutes on this side.
Remove patties from pan or grill. Place on the buns and top with any desired condiments. Serve.