2 tbsp [30 ml] olive oil
¼ cup [60 ml] butter

1 large yellow onion, finely and evenly diced
4 small (or 2 very large) carrots finely diced
4 stalks celery heart (or 2 large celery stalks) finely diced
4 garlic cloves, very finely diced
4.5 oz [125 g] diced pancetta (¼-inch cubes)
Kosher or sea salt
Freshly ground black pepper

2.2 lb [1 kg] lean ground meat (blend of veal, pork and beef – or just beef)
1 cup [250 ml] dry white wine (like a Chardonnay)
2 cups [500 ml] milk
1 28-oz [828 ml] can whole San Marzano tomatoes, diced (both the liquid and the tomatoes)
1 cup [250 ml] beef stock