This recipe is from the Orange County Register (3/16/05) and looks amazing. You can use any firm, thin white fish, as long as it's easy to roll up. The author writes "chopped chives add color and flavor to the cauliflower purée. Spoonfuls of the purée are wrapped with blanched chard leaves, making little oblong bundles, which are easy to roll the fillets around. The dish, cooked in the oven, is finished à la piccata, with shallots and some capers." The cauliflower puree and the chard leaves can be prepared the day before. She recommends serving it with Sauvignon Blanc. I haven't yet tried this recipe.