Thinly slice one large green cucumber and one medium-sized onion (if liked). Sprinkle over about one teaspoonful of salt. Allow to stand a short time,then place in a piece of cheese-cloth and squeeze out all the moisture possible. Place cucumbers,when drained,in the dish in which they are to be served,add a couple tablespoonfuls of sour vinegar,mix well. Then pour over enough thick sour cream to half cover and a dust of pepper.