Finely chop the onion, carrot, and celery.
Sauté the vegetables in a pan with olive oil.
Add ground beef and ground pork, and cook until browned.
Add tomato paste and minced garlic, and mix well.
Pour in white wine or red wine and cook off the alcohol.
Add chopped tomatoes, bay leaf, salt, and pepper, and bring to a simmer.
Simmer over medium-low heat for 30 to 40 minutes.
Taste for seasoning and finish.