Preheat oven in Convection Bake to 375°F (*350°F).
Combine shredded cheese and sour cream. Set aside.
Brush fish on both sides with melted butter. Sprinkle with tarragon, salt and pepper. Place fillets in 3-quart (9" x 13") baking dish.
Convection Bake for 10 minutes. Top with cheese mixture.
Convection Bake for and additional 10 to 15 minutes or until fish flakes easily with fork.