In a bowl, add miso, mirin, soy sauce, and sesame oil and mix well.
Spread the miso sauce evenly over the salmon fillets. Marinate in the refrigerator for 30-60 minutes.
Using the oven: Preheat the oven to 200℃/392゜F. Place the salmon on a baking sheet lined with aluminum foil and bake for approximately 12-15 minutes. Bake until the salmon is well-cooked and slightly browned on the surface.
Place the grilled salmon on a plate. Serve with rice and stir-fried greens.