Heat the butter in a skillet, add onions, and fry until golden. Add mushrooms and 2 tablespoons water, cover and cook on low heat for 5 minutes. Soak the bread in water, squeeze. Put everything through a grinder, season with salt and pepper. Mix until creamy. Spoon a little of the stuffing into the center of each pancake and fold the pancakes envelope fashion to encase the stuffing completely. Roll each stuffed pancake in leftover batter and in bread crumbs. Fry in hot butter until golden on both sides. Yields 15 pancakes.