Mix butter, 1 ½ tablespoons lemon juice, chopped chives, mustard, lemon peel, salt and pepper in a small bowl until well blended. Can be prepared two days ahead. Cover and refrigerate. Bring to room temperature before using.

Position rack in center of oven and preheat oven to 450°. Line rimless baking sheet with foil. Rub one tablespoon mustard chive butter over foil. Place fillets skin side down on foil. Spoon one teaspoon of lemon juice over the fillet. Season with salt and pepper. Top each fillet with one tablespoon mustard chive butter. Bake until fish is just cooked through, about 10 minutes. Using slotted spatula, transfer fish to plates. Garnish with chives and serve.