Preheat 10-12 inch frying pan (tastes best if you use cast iron). Pour in the oil. While pan is heating chop fat back. Cook fat back until desired crispness. While fat back is cooking, chop onion fine. Add onions and cook over medium heat until tender. Add stewed tomatoes.
While all this is cooking over medium low heat, cook pasta as directed on spaghetti package. When done, pour into colander and drain.
Add spaghetti to frying pan and mix well. Lower heat to low and let simmer for about 20 to 30 minutes. Serve hot yummm yummm!