Directions

1. In a bowl, combine the beef, salt, pepper, ketchup, and Worcestershire sauce and mix well. Shape into eight 1/4-inch thick patties.
2. Assemble the 4 burgers by layering a slice of mozzarella between two beef patties, then pinch around the edges to seal the cheese in.
3. Cook the patties over medium heat for 5 to 6 minutes on each side until the internal temperature reaches 160 degrees Fahrenheit.
4. Serve on toasted hamburger buns with tomatoes and pickles.