Heat a large oven-safe skillet or Dutch oven over medium-high heat. Add the ground beef and diced onion, then cook for 6–8 minutes while breaking the beef into small pieces, until browned and the onion is softened. Drain excess grease if necessary.

Add the minced garlic, kosher salt, black pepper, and Worcestershire sauce. Stir and cook for about 30 seconds, just until the garlic is fragrant.

Stir in the tomato sauce, undrained diced tomatoes, and beef broth. Bring the mixture to a boil, scraping the bottom of the skillet so the browned bits blend into the sauce.

Stir in the uncooked elbow macaroni. Reduce the heat to medium-low, cover, and simmer for 12–15 minutes, stirring occasionally, until the pasta is tender. Add a small splash of broth or water if the mixture becomes too thick before the pasta is cooked.

Stir 1 cup of the shredded cheddar into the hot pasta mixture. Sprinkle the remaining 1 cup over the top.

For a stovetop finish, cover the skillet for 2–3 minutes until the cheese melts. For a browned topping, place the oven-safe skillet in a 400°F oven for 5–8 minutes, or briefly under the broiler while watching carefully.

Let the casserole rest for 5 minutes before serving. Garnish with parsley and favorite cheeseburger toppings such as pickles, chopped tomatoes, shredded lettuce, diced onion, ketchup, or mustard.