1. Cut onion into wedges and place in a food processor. Add garlic, vinegar, cumin, red pepper flakes, oregano, salt and cayenne. Whirl until onion is very finely chopped, stopping to scrape down sides as necessary.

2. Spread both sides of ribs with onion mixture. Place ribs in a resealable plastic bag or flat dish. Close bag or cover dish and refrigerate for at least 6 hours or up to 1 day. Turn ribs once during marinating time.

3. When ready to cook, oil grill and preheat barbecue. Set barbecue temperature to medium or medium - low. Barbecue with lid down or loosely covered with foil, turning once or twice, until deep golden with slightly singed areas, about 50 to 60 minutes. If ribs are browning too quickly, move to a cooler part of grill or reduce heat. For appetizers,serve individual ribs.

Yield: 4 servings