Cut off the earthy ends of the mushrooms and clean them with a damp cloth. Cut too big mushrooms into pieces. Peel and finely chop the garlic cloves. Wash parsley, shake dry, pluck leaves from the stalks and chop coarsely.
Heat the oil in a large frying pan. Fry the mushrooms in it until they have lost their water. Drain the chestnuts in a sieve. Add wine and chestnuts to the pan and cook stirring until the wine has evaporated. Add butter, garlic and parsley. Stir over low heat for about 2 minutes. Then season with salt and pepper.