1/4 cup extra-virgin olive oil
1 medium onion, finely diced
1 medium carrot, finely diced
1 medium celery rib, finely diced
2 ounces thickly sliced pancetta, finely diced
1/2 pound ground beef
1/2 pound ground veal
1/4 pound ground pork
2 large garlic cloves, chopped
3/4 cup dry white wine
One 28-ounce can peeled Italian tomatoes—seeded and finely chopped, juices reserved
1 cup chicken stock or canned low-sodium broth
1/2 teaspoon dried thyme
1 bay leaf
Salt and freshly ground pepper
1/4 cup heavy cream
2 pounds penne rigate
Freshly grated Parmesan, for serving