In a large dutch oven pot, heat the oil over a medium flame. Add the onions and garlic, celery and carrots (optional) and sauté until the onions are translucent, about 10 minutes.
Turn flame down to a simmer and slowly add the tomato puree, tomato paste, bay leaf, salt and oregano to taste.
Then add a splash of red wine. Add the meats.
Stir now and then and simmer covered over low heat until the sauce thickens, about 3 hours.