Stir fry onion and celery, until onion is golden.
Add peeled tomatoes, salt and pepper.
Simmer for about 1/2 hour. At the end add butter.
Add to cooked, drained spaghetti and place over medium fire for a
few minutes so they absorb some of the sauce.
Serve hot. No cheese is normally sprinkled over this dish, but
some chilies may be used if so desired.