Freshly gathered, you clean them as best you can without washing them, leaving them whole but paring the tip of the stem. Put them in an earthenware or enamelled pan on a very low heat with the lid on. Almost at once they will render some of their liquor in which they continue to cook until this evaporates, care being taken not to let them stick. At this point add a good piece of fresh butter, salt and pepper. Cook till tender, a few minutes. At the moment of serving pour some fresh cream into the pan, stir vigorously and pour the contents onto a dish.
The initial cooking in their own juice is significant, a way of tenderizing a mushroom inclined to be tough.