Preheat oven to 425 degrees and grease a large baking sheet.

Wash and dry the salmon thoroughly, then place on prepared baking sheet.

In a small bowl, combine butter, 1 Tbsp sesame oil, miso, maple syrup, ginger powder, garlic powder, and mirin. Whisk to combine, then spread onto the salmon evenly. Allow salmon to sit for at least 30 minutes.

Heat a large skillet with 1 Tbsp of sesame oil. Heat over medium-high. When oil is hot, add in the bok choy cut side down. Allow to sear for 2-3 minutes, then add in the 1 tsp tamari. Shake the pan to distribute the sauce, and allow bok choy to cook for 2 more minutes on medium-high. When the cut side is slightly browned, flip bok choy and reduce heat to medium-low. Add 1 tsp water and cover. Steam bok choy until they reach your desired texture, 4 minutes for a tender texture.

Place salmon in oven and bake for 11-13 minutes. Remove from the oven and allow to rest for a few minutes before serving with the steamed bok choy and scallions. Don't forget to eat the crunchy caramelized miso that melts onto the pan, as it's delicious!