Combine the soy sauce, mandarin juice, mandarin zest, honey, hot pepper sauce,
and the fresh cilantro and shake in a sealed, resealable plastic bag until blended.
Add the tuna steaks and coat each side with the marinade. Seal and place the steaks
in the refrigerator to marinate for 30 to 60 minutes, turning the bag once.
Preheat the grill to high. With a slotted spatula, remove the tuna steaks from the
marinade. Strain the marinade into a small saucepan and boil to a thick, syrupy
glaze. Grill the fish until cooked to taste, 4 to 6 minutes per side for medium.
the tuna steaks with the glaze as they grill. Serve immediately.