Keeping the skin of the whitefish intact and the head still attached, carefully remove the bones from the whitefish and place the meat in a mixing bowl. Dice the celery and combine with the whitefish, along with 1 cup of the sour cream, the mayonnaise, and the pepper. Add the dill and parsley and as much more sour cream as is wanted. Stuff the mixture back into the skin of the whitefish, remaking the shape of a fish. Garnish with additional dill and parsley.
