Steps
1. Preheat your oven to 200°C (400°F).
2. In a small bowl, mix the miso paste, mirin, soy sauce, and sesame oil until smooth to create the marinade.
3. Place the salmon fillet on a baking sheet lined with parchment paper.
4. Brush the miso marinade generously over the salmon fillet, ensuring it's well coated.
5. Bake in the preheated oven for 10-12 minutes, or until the salmon is cooked through and flakes easily with a fork.
6. Once cooked, remove from the oven and let it rest for a minute.
7. Garnish with chopped green onion and sesame seeds before serving.
8. Serve with steamed rice if desired.