Instructions:
- Prepare the Glaze: In a medium bowl, combine the white miso paste, mirin, sake, sugar, soy sauce, and grated ginger. Whisk vigorously until the mixture is completely smooth.
- Marinate the Salmon: Pat the salmon fillets very dry with paper towels. Place the fillets in a shallow dish and pour the miso glaze over the fish, ensuring all sides are well coated.
- Chill: Cover and refrigerate. Allow the salmon to marinate for a minimum of 30 minutes, but ideally 2 to 4 hours.
- Preheat & Prepare: Preheat your oven to 400°F (200°C / Gas Mark 6). Line a baking sheet with parchment paper.
- Arrange Salmon: Remove the salmon from the marinade, gently wiping off most of the excess glaze, leaving only a thin coating. Place the fillets skin-side down on the prepared baking sheet.
- Bake: Bake for 12 to 15 minutes, depending on the thickness of the fillet, until the fish flakes easily and the internal temperature reaches 145°F (63°C). The glaze should be slightly darkened.
- Broil (Optional Quick Finish): If the top hasn't browned enough, switch the oven to the broiler (grill) setting for the final 1–2 minutes, watching very closely to prevent burning.
- Rest & Serve: Let the salmon rest for 5 minutes before serving.