1 large onion, chopped
8 slices bacon, cut into 1" pieces
1 can (15 oz.) tomato sauce
1 cup water
2/3 lb. spaghetti, cooked to al dente

Saute bacon in a large skillet.  Once it begins to brown and crisp, spoon off much of the grease into a cup and reserve.  Push bacon to the side, add onion to skillet and saute in grease.  Once softened, add tomato sauce and water.  Add cooked spaghetti to skillet and let simmer 10 minutes.  Spoon excess bacon grease over the top of each serving.