Directions

1. Preheat an outdoor grill for medium heat, and lightly oil the grates. Tear off two sheets of aluminum foil about 30 inches long, and place onto a work surface.
2. Divide the pork ribs in half, and place half the ribs in a single layer on each sheet of aluminum. Spread the mustard onto both sides of the ribs. Place the brown sugar, paprika, garlic powder, onion powder, black pepper, and cumin in a bowl, and mix until thoroughly combined. Generously rub the spice mixture onto both sides of the ribs.
3. Fold the excess aluminum sheet to make a double-thick top layer; pinch and fold the top and sides together to completely enfold the ribs in foil, leaving room for heat to circulate.
4. Place the two packets of ribs onto the preheated grill, close the lid, and grill until the meat is tender and thoroughly cooked through, about 45 minutes. An instant-read meat thermometer inserted into the thickest part of a rib should read at least 160 degrees F (70 degrees C). Remove ribs from foil, and discard foil.
5. Return the ribs to the grill, brushing each side with the steak marinade. Grill until the ribs show charring and good grill marks and the steak marinade cooks onto the outside of the ribs, about 15 more minutes. Turn and baste occasionally with marinade.