Wash, cook and drain spinach and pass through a strainer. Soak rolls in milk, squeeze dry and pluck to pieces. Saute rolls, onions and parsley in butter. Add spinach and let simmer briefly. Remove from heat, stir in egg yolks and seasonings. Let cool. Fold in well-beaten egg whites. Pour into greased pudding form, set in water and cook over moderate heat for one hour. Serve with a spicy sauce and salads.