Lamb Bolognese with Herbs & Parmesan

Ingredients

• 1 large onion, chopped
• 2 stalks celery, chopped
• 2 carrots, peeled and chopped
• Olive oil
• 2 lb ground lamb
• Kosher salt
• 1/2 C tomato paste
• 1 1/2 C white wine
• 1 qt chicken stock
• 1 C whole milk
• 1 bay leaf
• 2 sprigs thyme
• 2 sprigs rosemary
• 2 sprigs oregano
• 2 lb dried pasta
• 1/2 C grated parmigiano reggiano
• 2 T butter