Plank-Grilled Tuna Steaks

Thaw fish, if frozen. Rinse the fish; pat dry with paper towels. Whisk together the rice vinegar, scallion, lime peel, lime juice, ginger, sesame oil, cilantro, soy sauce, garlic, salt, and crushed red pepper in a shallow dish. Reserve 1/4 cup of the marinade; set aside. Add the tuna steaks to the dish, turning to coat. Cover and marinate in the refrigerator for 1 hour, turning the steaks once. Meanwhile, soak the cedar plank in water for at least 30 minutes.

Drain and discard the marinade from the fish. Remove the cedar plank from the water. Cut bok choy bunches in halves lengthwise; set aside.

For a charcoal grill, place the cedar plank on the grill rack directly over medium-hot coals. Cover and grill for 3 minutes or until it begins to crackle and smoke. Turn plank over. Place the tuna steaks on the plank. Cover and grill the plank for 12 to 15 minutes or until the tuna begins to flake when tested with a fork (the fish will be slightly pink in the center). Do not turn the tuna. Grill the bok choy on the grill rack directly over the coals for 2 to 3 minutes or until wilted, turning once. (For a gas grill, preheat grill. Reduce heat to medium-hot. Place the plank on the grill rack over heat. Cover and grill as directed.) Drizzle the bok choy with the reserved marinade mixture. Sprinkle the bok choy and tuna with sesame seeds.