In a bowl, whisk together soy sauce, mirin, brown sugar, sesame oil, garlic, and ginger to create the marinade.

Place the salmon fillets in a shallow dish and pour the marinade over them. Let marinate for at least 15 minutes.

Preheat your grill or skillet over medium-high heat.

Remove the salmon from the marinade and reserve the marinade for later use.

Cook the salmon fillets for about 4-5 minutes on each side, or until cooked through and flaky.

While the salmon cooks, pour the reserved marinade into a saucepan and bring to a boil.

Reduce heat and simmer for 5 minutes until slightly thickened.

Brush the thickened marinade over the salmon during the last minute of cooking.

Remove the salmon from the heat and let rest for a couple of minutes.

Serve the salmon garnished with sesame seeds and green onions, alongside steamed broccoli and rice.