Preheat the oven to 425ºF, then line a baking sheet with parchment paper.
Place the salmon fillets on the baking sheet, then lightly pat them with paper towels to remove excess moisture. Season with a bit of salt and set aside to sit at room temperature for 15 minutes.
In a small bowl, whisk together the ingredients for the miso glaze until a paste forms. Add about ½ tablespoon of water and stir until it becomes a smooth sauce. Brush a generous amount of the miso glaze over the fillets with a pastry brush.
Transfer the fillets to the oven and bake for 8-12 minutes, depending on the thickness. Check the internal temperature at the 8-minute mark to see where you're at. You want an internal temperature of between 130ºF (medium) and 140ºF (medium-well).
When done, remove the fillets from the oven, garnish with toasted sesame seeds and sliced green onions, and serve.
