Classic Ragu Bolognese

INGREDIENTS

• 6 ounces ground veal
• 2 carrots, peeled, finely chopped (about 3/4 cup)
• Kosher salt and freshly ground black pepper
• 2 celery stalks, finely chopped (about 1 cup)
• 2 tablespoons extra-virgin olive oil
• 3 ounces thinly sliced pancetta, finely chopped
• 1 pound tagliatelle or fettuccine (preferably fresh egg)
• Finely grated Parmesan (for serving)
• 3 cups (about) beef stock or chicken stock, divided
• 3 tablespoons tomato paste
• 1 cup whole milk
• 6 ounces ground beef (85% lean)
• 1/2 cup dry red wine
• 2 medium onions, finely chopped (about 1 1/2 cups)