The California origins of this delectable sauce are easy to find. In fact, this might be one rib recipe that should be served with wine! A good, hearty, California Zinfandel would be a superb match.
In a medium saucepan heat oil over medium heat. Add onion; cook about 10 minutes or until tender, stirring occasionally. Add tomato puree, dried plums, brown sugar, the water, mustard, lemon juice, Worcestershire sauce, hot pepper sauce, allspice, and ginger. Bring to a boiling; reduce heat. Simmer gently, uncovered, for 5 to 10 minutes or until sauce thickens. Season to taste with salt and pepper.
Trim fat from ribs. Prepare grill for indirect grilling. Test for medium heat above the drip pan. Place ribs, bone sides down, on the grill rack over the drip pan. Cover and grill for 1-1/2 to 2 hours or until tender, brushing occasionally with sauce during the last 10 minutes of grilling. Reheat any remaining sauce until bubbly; serve with ribs. Makes 4 servings.