You can add wine, herbs or cream to this recipe, which should be served as a side dish to roast meats. PREHEAT OVEN TO 350F. Clean leeks; remove all withered leaves and trim the roots carefully. Without cutting entirely through the root, slit the leeks lengthwise to remove all of the dirt. Trim to a total length of about 8 inches (save the trimmings for stock). Place the leeks in a baking dish in 1 layer. Pour in enough water or stock to come about halfway up the leeks. Dot with butter and salt and pepper to taste. Set the baking dish over high heat on the stove top and bring to a boil. Cover and braise in oven for 30-to-40 minutes or until the whites of the leeks are tender. The cover may be left slightly ajar to evaporate some of the liquid. Sprinkle with butter or minced parsley and serve.