Preheat oven to 425°F. Lightly grease a 9″ pie dish. Sift flour, salt, sugar and baking powder. Add the butter and shortening and cut in with two knives or a pastry blender until crumbly. Add beaten eggs and wine and stir until all the mixture is dampened. Knead lightly and divide mixture into two parts. Roll out half the mixture to 1/2″ thickness. Line pie dish with pastry and fill as desired (3 cups approx of ground beef, poultry, fish, fruit, vegetables or guava paste). Fold the bottom edges over the top and varnish with beaten egg. Make cuts in the top so that pastry does not burst when baking. Bake at 425°F. for 10 mins. and then at 350°F. for a further 30 or 40 mins. Serves 8.