A sweet-salty miso, brown sugar, and soy sauce glaze caramelizes in about 10 minutes as it cooks atop rich, meaty salmon.
Combine first 4 ingredients, stirring with a whisk. Arrange fish in a shallow baking dish coated with cooking spray. Spoon miso mixture evenly over fish.
Broil 10 minutes or until fish flakes easily when tested with a fork, basting twice with miso mixture. Sprinkle with chives.