Line a baking pan with parchment or foil for easy clean up. Pat the halibut fillets dry and arrange fillets, skin side down (if your pieces have skin), on the baking pan with 2” around each fish piece.
Mix the ingredients for the Asian sauce in a small container and stir well to combine. Carefully spoon the Asian sauce over the fish pieces (it will pour off the sides and pool around the fish). Arrange the baking dish on the oven rack, being careful not to spill, and cook for 10 minutes.
Open the oven and baste the fish with the sauce that has pooled around the fish (it will be thicker and somewhat sticky now it’s been in the oven). After another 2 minutes of cooking, remove the baking pan from the oven and let the fish rest for 5 minutes.
Transfer the halibut to a serving tray and spoon all the thickened sauce that has pooled on the parchment onto the fish. Sprinkle with lime zest and green onion slices. Garnish with cilantro leaves. Serve with rice to soak up the extra sauce.