Salt and freshly ground black pepper
Several big leaves of romaine lettuce, Bibb lettuce or white cabbage
1 1/2 pounds thick white fish fillet (rockfish, cod, hake, snapper), in pieces about 3/4 to 1 inch thick, 1 inch wide, and 2 inches or less across
1 cup white wine, approximately
2 to 3 tablespoons butter
Bring a large pot of water to a boil and salt it. Take as many big, intact leaves of lettuce or cabbage as you have pieces of fish. With large outer leaves, cut out center veins 2 to 3 inches up from bottom of leaves, to the point where the leaf is more pliable; with inner leaves this may not be necessary. One or 2 at a time, blanch leaves in boiling water until they are tender and flexible, 30 seconds to a minute. Remove and drain on paper towels.
Put a piece of fish on each leaf and sprinkle with salt and pepper; fold or roll fish in leaf so edges overlap. It is not important to make a tight seal, but it is nice if package covers all the fish. When done, you can cover and refrigerate packages until ready to serve, or continue.
In a large, broad skillet or casserole with a cover, bring wine to a boil with butter. Reduce heat to a simmer and add fish packages. Cover and simmer until a thin-bladed knife easily penetrates fish, 5 to 10 minutes. Remove fish to a warm platter.
Over high heat, quickly reduce liquid in skillet; it is likely there will be more than there was when you started. When it is thickened a bit, pour over fish and serve.
from Mark Bittman.