In a large bowl whisk the mustard into the beer, broth and vinegar. Place the short ribs, garlic cloves and sliced onion into a pan or casserole and pour the beer mixture over them. Toss gently to coat everything evenly, cover tightly with plastic wrap or lid and refrigerate overnight.
Preheat oven to 350 degrees. Remove the ribs from the marinade (reserve marinade) and blot dry with paper towels. Season with salt and pepper and dredge in flour.
In a heavy skillet warm the oil on medium-high heat until it appears watery and is just about to smoke. Add ribs and sear until well-browned on all sides, approximately 2 minutes each side. Transfer the browned ribs to an ovenproof pan (such as a Dutch oven), pour the onions, garlic and marinade back over them, cover tightly and place in oven to braise. Cook for 2 to 3 hours until the meat pulls away from the bones easily. (If you have the time, you can refrigerate your ribs for a few hours or overnight at this point. This makes it easier to remove the fat off the top, as it will congeal and you can simply scoop it off.)
Place a large casserole in the oven for the last couple of minutes of baking to warm. Remove the roasting pan from the oven and, using tongs or slotted spoon, transfer rib meat to the warm casserole and set aside. Using a ladle or large spoon, skim fat from top of roasting pan. Turn oven heat up to 400 degrees.
Strain remaining cooking juices into a saucepan, discarding onions and garlic, and reduce by half over medium heat, approximately 10 to 20 minutes. Add the vegetables, bring heat up to a simmer and cook until al dente, approximately 10 to 20 minutes. Season the sauce and vegetables to taste with salt and pepper. Pour the sauce and vegetables over the ribs in the casserole and return it to the 400-degree oven to warm through, approximately 5 to 7 minutes.
Serve with roasted fingerling potatoes, good crusty bread and more Fred.
-- From Greg Higgins, Higgins Restaurant
PER SERVING (based on 6 servings) : calories: 533 (47.5% from protein); protein: 45.6 grams; total fat: 28.1 grams; saturated fat: 10.4 grams; cholesterol: 134 mg; sodium: 268 mg; carbohydrate: 20.2 grams; dietary fiber: 3.3 grams