Combine your tomato puree, garlic, Italian seasoning, hamburger and vegetable cooking oil in a 4 quart pot. Cook until you prepare your spaghetti as directed on the box for al dente. When spaghetti is cooked add to sauce.
Cut up 1/2 the cheese into chunks, add to sauce and stir. Place other 1/2 of the cheese cut into slices on top of spaghetti.
Bake in a 350 degrees F oven for 35 to 40 minutes. Let rest 5 minutes after removing it from the oven.