Bring a large pot of salted water to a boil. Add elbow macaroni and cook according to package directions until al dente. Drain and set aside.

In a large skillet over medium heat, add the ground beef and cook until browned, breaking it apart with a spatula. Drain excess fat if necessary.

Add the diced onion and minced garlic to the skillet. Cook until the onion is translucent, about 3-4 minutes.

Stir in the ketchup, Worcestershire sauce, brown sugar, mustard, salt, and black pepper. Mix well and let it simmer for about 5 minutes.

Combine the cooked macaroni with the beef mixture, stirring until the pasta is evenly coated.

Sprinkle the shredded cheddar cheese on top and cover the skillet. Let it cook for an additional 5 minutes until the cheese is melted.

Garnish with sliced green onions before serving.