Preheat the oven to 375 degrees F (190 degrees C).
Mix honey, green onions, soy sauce, sesame seeds, garlic, onion, ginger, and red pepper flakes in a small bowl until blended.
Place salmon in single layer in a 9x13-inch baking dish. Spoon honey mixture evenly on top of salmon; the mixture will run off, but try to coat the fish with a thin layer all over.
Roast salmon in the preheated oven, basting salmon with the sauce at least once, until fish flakes easily with a fork, about 20 minutes.
