Grease a 15x25cm loaf pan, line base and sides with parchment paper, then grease paper. Cream butter and sugar in a small bowl with electric mixer only until combined. Add eggs quickly, one at a time. Beat until combined. Transfer mixture into a large bowl. Stir in fruit, then half of the sifted flours with the combined milk and Sherry. Stir in remaining flour and milk mixture. Spread mixture into prepared pan. Bake in moderately slow oven for about 2 hours. Cover with foil, cool in pan.