In a mixing bowl, combine the honey, soy sauce, minced garlic, rice vinegar, and red pepper flakes (if using). Mix well to create a marinade.
Add the salmon pieces to the marinade, ensuring they are well coated. Let them marinate for about 5 minutes while you prepare the cornstarch coating.
In a separate bowl, season the cornstarch with a little salt and pepper.
Remove the salmon pieces from the marinade, allowing any excess marinade to drip off, then coat each piece with the seasoned cornstarch, shaking off the excess.
Heat the vegetable oil in a frying pan over medium heat. Once hot, gently add the coated salmon bites in a single layer. Do not overcrowd the pan.
Cook the salmon bites for about 3-4 minutes on each side, or until golden brown and crispy.
Once cooked, remove them from the frying pan and place them on a plate lined with paper towels to absorb any excess oil.
Drizzle the remaining marinade over the crispy salmon bites and garnish with chopped green onions before serving.