Marinade: Heat vegetable oil in large saucepan over low heat. Add onions and garlic and saute for 10 minutes, until the onions are translucent but not browned. Add tomato paste, vinegar, honey, worcestershire sauce, mustard, soy sauce, hoisin sauce, chili powder, cumin, and red pepper flakes. Simmer uncovered over low heat fro 30 minutes. Set aside half of the marinade for serving.
Meanwhile, preheat oven to 350 degrees. Place the ribs on a baking sheet, slather both sides with marinade, and bake for 1 hour.
Place ribs on hot grill and cook for 3-5 minutes until one side is nicely browned. Turn the ribs and close the cover of the grill, making sure vents are open enough to allow airflow, but not so much that there are flames around the meat. Grill the ribs for 10 more minutes, turning if necessary.
Place ribs on a platter, brush with reserved marinade, and wrap tightly in aluminum foil. Allow to rest for 10-15 minutes. Slice between ribs and serve hot with the remaining reserved marinade for dipping.