In a large pot (8 quart) place the ribs, onion, garlic, peppercorns, salt and bay leaf. Add enough water (4 quarts) to generously cover. Bring to boiling over medium-high heat. Reduce to a simmer and cook 45 minutes, occasionally skimming foam off the top of the pot. Drain and cool; reserving only the ribs. (This step may be done up to 24 hours in advance; refrigerate after cooling.)
Meanwhile in a medium-size saucepan, combine the ketchup, vinegar, brown sugar, molasses, Worcestershire sauce, onion powder, mustard powder, liquid smoke, garlic salt and pepper. Bring to a boil over medium-high heat, and simmer 10 minutes, stirring occasionally (makes about 2 cups). Can be done ahead of time and refrigerated until ready to use.
Heat gas grill to medium-high or prepare charcoal grill with medium-hot coals. Liberally coat meaty side of ribs with sauce. Grill, sauce side down, 5 minutes. Coat second side with sauce, and flip over ribs. Grill 5 minutes. Coat meaty side again with sauce, and flip over one last time. Grill 5 minutes until slightly charred and crispy. Serve immediately with any remaining sauce.To Broil: Broil, sauce side up, 5 minutes. Turn ribs over and coat with sauce. Broil 5 minutes. Turn once more, coat meaty side with sauce and broil 5 minutes. Serve. Makes 6 servings.