Bring a large pot of lightly salted water to a boil. Add pasta and cook for 8 to 10 minutes or until al dente; drain, and set aside.
Brown ground beef in a large skillet over medium high heat, stirring to crumble; drain, and set aside. Heat oil in a separate skillet over medium high heat. Cook potatoes for 2 minutes, then stir in onion. Continue cooking until well browned, then carefully drain excess oil.
Combine potatoes with ground beef mixture, and stir in tomato sauce and cubed cheese. When cheese has melted, stir in noodles and continue cooking 15 minutes more. Serve immediately.