Heat oven to 325 or start your barbecue. (I always do mine on the bbq)
Prepare spice rub: Mix paprika, salt, thyme, garlic powder, onion powder, celery seeds, and ground red pepper in a small bowl. Rub ribs with spice mixture. Place ribs in a single lawyer on racks of 2 broiler or roasting pans.
Bake in heated over for 1 hour (or slow roast them on the barbecue). Remove from oven.
Meanwhile, prepare sauce. Stir together tomato paste, beer, molasses, brown sugar, soy sauce, Worcestershire sauce, ginger, hot-pepper sauce and onion in a medium sized saucepan. Cook sauce, stirring occasionally, over a medium heat until thickened, about 15 minutes. Divide sauce in half: one half for basting, and one half for serving.
Brush both sides of ribs with most of the basting sauce. Return to oven (or barbecue).
Increase oven (or barbecue) temperature to broil. Broil ribs 4 to 6 inches from heat for 8 minutes. Turn ribs over; baste with remaining basting sauce. Broil 8 to 10 minutes. Serve with reserved sauce.