12 firm fresh leeks 1" to 1-1/2" in diameter
2 cups beef stock
4 tablespoons butter
freshly ground black pepper
1. Cut off the roots of the leeks and strip away any withered leaves. Line up the leeks in a row and cut off enough green to make them all 6" or 7" long. Then with a sharp knife slit the green parts in half lengthwise, stopping where they shade into white. Carefully spread the leaves apart and wash them under fast-running water, looking out for any hidden pockets of snad. Lay the leeks in 1 or 2 layers in a heavy stainless-steel or enamelled skillet or flameproof casserole just large enough to hold them flat. Pour in the beef stock and add the butter. Bring the stock to a boil over high heat; reduce the heat and boil gently, basting occasionally, for 15 minutes, or until the white parts of the leeks are tender when pierced with a sharp knife.
2. Preheat the oven to 325 degrees. With tongs or a slotted spatula, arrange the leeks in one layer in a shallow, buttered baking dish. Taste the stock for seasoning, then pour it over the leeks and bake them covered loosely with a sheet of aluminum foil. In 20 minutes or so the leeks should be lightly colored and the stock almost cooked away. If the stock has not reduced enough, transfer it to a small saucepan with a bulb baster or spoon and boil it down. Serve the leeks directly from the baking dish or arrange them on a heated platter and pour the syrupy stock over them.