Mix miso, honey, mirin and ginger together. Spread on top of salmon fillet. Marinade overnight or if you’re in a hurry, broil immediately until just cooked through. My salmon fillet was quite thin, so it only took about 6 minutes to cook; however if you use a thicker piece of fish, you will need to cook it longer.
Heat dashi in a small saucepan. Stir in miso and bring to a boil. Add bok choy and mushrooms. Cook about 2 minutes or until just cooked.
To serve, place soba noodles in a bowl, top with bok choy and mushrooms and ladle miso soup on top. Gently place broiled Honey Miso Salmon on top. Sprinkle with scallion and sesame seeds.