Prepare the sole, season, pass through melted butter and coat with fine white breadcrumbs. Pat and shape it with the flat of a knife to make sure that the breadcrumbs adhere properly and mark it trellis-fashion with the back of the knife. Sprinkle with melted butter and place to grill gently under the salamander.
Place on a hot dish when ready and surround with potatoes trimmed olive shape and shallow fried in butter to a golden brown.
Serve accompanied with Sauce Béarnaise.