In a mixing bowl, whisk together the red miso paste, soy sauce, brown sugar, sake (or wine), rice vinegar, ginger, and garlic. The result should be a smooth, slightly thick marinade with a balance of salty and sweet.

Chef’s Note: Taste the marinade before adding the salmon. It should be strong—remember, it’s going to flavor the fish while cooking.

Place the salmon fillets in a shallow dish or a zip-top bag. Pour half the marinade over the fish, making sure each fillet is evenly coated. Cover and refrigerate for at least 30 minutes, but no longer than 2 hours.

Tip: Over-marinating can make the salmon too salty and overpower the natural flavor of the fish.

Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or foil for easy cleanup. Place the salmon fillets skin side down (if using skin-on). Brush with a bit of the reserved marinade.

Bake for about 12–15 minutes, depending on thickness. Salmon should flake easily with a fork but remain moist inside. As it bakes, the miso glaze will caramelize, creating that signature glossy finish.

Chef’s Tip: If you like a slightly charred finish, you can broil the salmon for the last 1–2 minutes.

While the salmon is baking, pour the remaining marinade into a small saucepan. Heat gently and stir in the softened butter until melted. This gives the glaze a rich, silky texture.

Place the salmon fillets on plates, spoon some of the buttery glaze on top, and garnish with sesame seeds or green onions if you like. Serve immediately while warm.