Make dough of cream cheese, margarine and flour. If dough is too soft knead in some of the extra flour. Wrap in foil and refrigerate for one hour. In a non-stick pan melt butter and fry the finely chopped onion till pinkish in colour. Add finely chopped mushrooms and seasonings, together with the flour. Cook for about five minutes to ensure that flour is not raw. Adjust seasoning if necessary. Set aside to cool. On floured surface with floured rolling pin roll out 1/2 of the dough 1/8" thick. Cut out circles of about 7 cm in diameter. Repeat with the remaining dough. Fill half of each circle with mushroom mixture. Fold over into half and press edges with a fork to seal. Prick tops of pastry with a fork gently to make tiny holes. Brush tops with a little milk and bake in a greased oven tray for 12-14 minutes or until golden brown. Serve hot with chili sauce.