The turbot is roasted on a thin cake of overlapping potato slices and then sauced with a simple pan sauce, garnished with tomatoes and black olives. Turbot is rarely available in the United States, but another flatfish such as a fluke or flounder makes a good substitute.
You will need a mandoline or other vegetable slicer to slide the potatoes very thin. Ovenproof nonstick frying pans work best here, so the potato cakes don't stick, but if necessary you can use other 8-inch frying pans or cake pans; line them with rounds of parchment paper.
