• 4 lamb shanks (about 3 1/2 pounds)
• 1/4 tsp. salt
• 1/4 tsp. freshly ground pepper
• 2 Tbsp. vegetable oil
• 1 large onion , chopped
• 2 carrots , peeled and chopped
• 1 celery stalk , chopped
• 3 cloves garlic , smashed
• 1 1/2 cups red wine
• 1/4 cup red wine vinegar
• 1 1/2 quarts reduced-sodium chicken broth
• 1 bay leaf
• 1 small fresh rosemary sprig
• 3 fresh thyme sprigs

Preheat oven to 350°. Season lamb with salt and pepper. Heat oil in a large ovenproof casserole over medium-high heat.

Add lamb and cook until browned on all sides, 6 minutes. Remove from pan and set aside. Reduce heat to medium.

Add onion, carrots, celery, and garlic to casserole; cook until golden, about 10 minutes. Increase heat to high. Add red wine and vinegar. Bring to a boil over medium-high heat and cook until reduced by two thirds, about 5 minutes.

Add broth and lamb to casserole; bring to a boil, then reduce to simmer (2 to 3 minutes). Meanwhile, tie together bay leaf, rosemary, and thyme with kitchen string; add to casserole. Cover and bake 1 to 1 1/4 hours, or until lamb is tender.

Remove lamb from casserole. Strain out vegetables and discard them, saving the liquid. Return liquid to casserole, bring to a boil over medium-high heat, and cook until reduced to 1 to 1 1/2 cups, about 20 minutes. 

Return lamb to the reduced braising liquid and keep warm until serving. To serve, spoon sauce over lamb.