Preheat The Oven'S Broiler And Set The Oven Rack About 6 Inches From The Heat Source. Line A Broiler Pan With Aluminum Foil. Place The Cod Fillets On The Foil, And Brush With Butter. Season With Lemon Juice, Tarragon, And Black Pepper; Sprinkle With Sesame Seeds. Broil The Fish In The Preheated Broiler Until The Flesh Turns Opaque And White, And The Fish Flakes Easily, About 10 Minutes.