Melt butter in a large skillet over low heat; add onion and garlic, and saute until tender. Add remaining ingredients, except ribs, and bring to a boil. Reduce heat, and simmer for 20 minutes, stirring occasionally.
Place large piece of aluminum foil over coals beneath grill to catch drippings.
Baste meatiest side of ribs with sauce. Place ribs on grill, meatiest side down, about 6 inches above low coals; baste top side. Close grill hood. Cook about 20 minutes; turn ribs, and baste. Cook an additional 45 minutes, turning and basting every 15 minutes.
Makes 3 to 4 servings.
Cajun Country -- New Iberia, Louisiana