Preheat oven to 325°.Preheat large skillet with small amount of vegetable oil.

Season short ribs with salt and pepper. Sear all sides to golden brown in skillet. (Do not over crowd skillet.) Place short ribs in deep roasting pan, single layer.

In a large sauce pan, heat mustard, BBQ sauce and beef stock. Pour heated mixture over ribs. Ribs should be covered with liquid. Cover pan and cook for 2 ½ to 3 hours. Meat should be falling off the bone.