Preheat your oven to 400°F (200°C) and position the rack in the middle; line a baking sheet with foil or parchment.

Mix white miso paste, mirin, soy sauce, honey, grated ginger, minced garlic, and sesame oil in a small bowl until smooth and glossy.

Pat salmon fillets dry; generously coat the flesh side and edges with glaze, letting excess drip back into the bowl.

Arrange fillets skin-side down on the prepared sheet; bake at 400°F (200°C) for 10–12 minutes until salmon is nearly opaque and flakes easily.

Switch oven to broil; cook 2–3 minutes more until the glaze bubbles and edges caramelize to a golden brown—watch closely.

Let salmon rest 2 minutes, then transfer to plates; garnish with sesame seeds and chopped spring onions.