Cook the spaghetti noodles according to package instructions. Once cooked, drain the noodles and set aside.
In a large saucepan over medium heat, add the oil. When oil is hot, add the chopped onions and cook until soft. Add the garlic and saute for about one more minute. You do not want the garlic to turn brown.
Add the ground beef and break them apart. Cook the beef until the color turns deep brown, about 7-10 minutes. Add salt and pepper to taste.
Pour in the spaghetti sauce and cream of mushroom. Stir the mixture using a whisk to produce a smooth sauce. Bring to a boil. Stir the sauce once or twice to ensure that nothing sticks at the bottom of the pan. Turn the heat off.
Pour the sauce over cooked noodles and top with grated cheese.