Preparation Mix wine, 1 tablespoon garlic, mustard and red pepper in large glass baking dish. Add short ribs; turn to coat. Cover and refrigerate overnight, turning occasionally. Preheat oven to 500°F. Using tongs, transfer short ribs to large roasting pan; reserve marinade. Sprinkle short ribs with salt and pepper. Roast until brown, turning once, about 30 minutes. Transfer short ribs to large bowl. Place roasting pan over 2 burners. Heat over medium-high heat. Add 1 cup beef stock to pan and bring to boil, scraping up any browned bits. Pour pan juices into bowl with short ribs. Reduce oven temperature to 350°F. Heat oil in heavy large ovenproof pot over medium-high heat. Add carrots, celery, onions and 2 tablespoons garlic. Sauté until vegetables are tender, about 12 minutes. Add short ribs and pan juices, reserved marinade, 2 3/4 cups beef stock, chicken stock, thyme and bay leaves. Bring to boil. Cover pot and place in oven. Bake until ribs are tender, about 2 hours. Using tongs, transfer short ribs to large bowl. Boil cooking liquid until reduced to thin sauce consistency, about 25 minutes. Strain liquid; discard solids and return liquid to pot. Dissolve cornstarch in 1/4 cup water. Whisk into cooking liquid. Boil until sauce thickens and coats spoon, stirring constantly, about 2 minutes. Season with pepper. Return ribs to pot. Simmer until heated through, 3 minutes. Transfer to platter. Garnish with thyme.
Preparation Mix wine, 1 tablespoon garlic, mustard and red pepper in large glass baking dish. Add short ribs; turn to coat. Cover and refrigerate overnight, turning occasionally. Preheat oven to 500°F. Using tongs, transfer short ribs to large roasting pan; reserve marinade. Sprinkle short ribs with salt and pepper. Roast until brown, turning once, about 30 minutes. Transfer short ribs to large bowl. Place roasting pan over 2 burners. Heat over medium-high heat. Add 1 cup beef stock to pan and bring to boil, scraping up any browned bits. Pour pan juices into bowl with short ribs. Reduce oven temperature to 350°F. Heat oil in heavy large ovenproof pot over medium-high heat. Add carrots, celery, onions and 2 tablespoons garlic. Sauté until vegetables are tender, about 12 minutes. Add short ribs and pan juices, reserved marinade, 2 3/4 cups beef stock, chicken stock, thyme and bay leaves. Bring to boil. Cover pot and place in oven. Bake until ribs are tender, about 2 hours. Using tongs, transfer short ribs to large bowl. Boil cooking liquid until reduced to thin sauce consistency, about 25 minutes. Strain liquid; discard solids and return liquid to pot. Dissolve cornstarch in 1/4 cup water. Whisk into cooking liquid. Boil until sauce thickens and coats spoon, stirring constantly, about 2 minutes. Season with pepper. Return ribs to pot. Simmer until heated through, 3 minutes. Transfer to platter. Garnish with thyme.