In a large skillet, heat the olive oil over medium heat. Add the chopped onion and minced garlic, sautéing until the onion is translucent, about 3-4 minutes.
Add the ground beef to the skillet. Cook until browned, breaking it up with a spoon, about 5-7 minutes. Drain excess fat if necessary.
Stir in the diced tomatoes (with juice), beef broth, and Italian seasoning. Bring to a simmer.
Add the elbow macaroni to the skillet, stirring well to combine. Cover and cook for about 10-12 minutes, or until the pasta is tender, stirring occasionally.
Once the pasta is cooked, remove the skillet from heat and stir in the shredded cheddar cheese until melted and creamy. Season with salt and pepper to taste.
Garnish with fresh parsley before serving.