Brown the ground beef in a large skillet over medium heat. Break it up as it cooks until no pink remains.
Add the diced onion and minced garlic to the skillet. Cook for 2 minutes until the onion softens.
Stir in the elbow macaroni, beef broth, tomato sauce, ketchup, and mustard. Bring the mixture to a boil.
Reduce the heat to low, cover the skillet, and simmer for 12 minutes. Stir once halfway through to keep the pasta from sticking.
Remove the skillet from the heat. Sprinkle the shredded cheddar cheese over the top and stir until it melts into the sauce. Season with salt and pepper.
Serve the skillet hot with sliced pickles on the side.