In a small bowl, whisk together the soy sauce, honey, rice vinegar, sesame oil, garlic, and ginger until well combined.
Place the salmon fillets in a shallow dish and pour the marinade over the top, ensuring the salmon is well coated. Cover and refrigerate for at least 30 minutes, or up to 2 hours for more flavor.
Preheat your grill or a non-stick skillet over medium-high heat.
Remove the salmon from the marinade, reserving the marinade for later.
Cook the salmon fillets for about 4-5 minutes on each side, or until they are cooked through and flake easily with a fork.
While the salmon is cooking, pour the reserved marinade into a small saucepan and bring to a boil. Reduce heat and simmer for about 5 minutes until slightly thickened.
Drizzle the thickened sauce over the cooked salmon fillets.
Garnish with chopped green onions and sesame seeds before serving.