Divide the ground beef into two equal portions and roll them into balls. Flatten each into a patty slightly larger than your burger bun to allow for shrinkage during cooking. Sprinkle both sides with salt and pepper.
½ pound ground beef, Salt and pepper
Preheat the grill to high heat. Place the cut sides of the buns face up on a tray and toast for 3 to 5 minutes, or until golden brown. Set them aside.
2 soft burger buns
Heat the olive oil in a large cast iron skillet over high heat. Once hot, add the burger patties and cook for 2 minutes, pressing lightly with a spatula. Flip the patties, place a slice of cheddar cheese on each, and cook for another 2 minutes. Remove from heat and let them rest for 3 minutes before assembling.
1 tablespoon olive oil, 2 slices Cheddar cheese
Mix the ketchup and Worcestershire sauce, then spread it onto the bottom bun. Layer with romaine lettuce, tomato slices, and onion rings. Place the burger patty with melted cheese on top, followed by the top bun. Add more sauce if desired.
4 romaine lettuce leaves, 1 large tomatoes, 1 red onion, 2 tablespoons ketchup, 1 tablespoon Worcestershire sauce
Serve immediately with your favorite sides, such as French fries or a crisp salad.