How to Make It
Whisk together hoisin, rum, soy sauce, honey, sambal, sesame oil, ginger, garlic, five-spice, onion powder, and food coloring in a medium bowl, reserving 1/4 cup.
Place ribs in a large ziplock plastic bag. (You may need more than 1 bag, and you may need to cut ribs in half.) Add hoisin mixture, seal tightly, and rub to coat. Chill at least 4 hours or overnight.
Prepare a charcoal grill to medium (350°F to 400°F), by piling charcoal on 1 side of grill and leaving other side empty. (For gas grill, light only 1 side.) Remove ribs from bag, and discard marinade. Sprinkle salt and pepper over ribs, and place slabs on unlit side of grill, stacking 1 on top of the other. Grill, covered, 40 minutes. Rotate slabs, moving bottom slab to top; grill, covered, 40 minutes. Rotate again; grill, covered, 40 minutes.
Decrease grill temperature to 300°F to 350°F (medium); place slabs side by side on unlit side of grill. Baste with reserved 1/4 cup sauce. Grill, covered, 30 minutes, basting with sauce occasionally. Remove from grill; let stand 10 minutes before cutting.
Cut slabs into individual ribs, and sprinkle with chives; serve immediately.