Lightly oil your muffin tin with the vegetable oil.
On a lightly floured surface, roll the pastry out to a thickness of 3mm. Cut circles for the base of the pies. The circles should be big enough so that the edges extend slightly higher than the edge of the pan. This will enable you to seal the pies properly.
Cut enough circles for the top of the pies. These should be slightly smaller than the bases. Ease the large pastry circles carefully into the pan.
In a bowl, combine all the ingredients for the filling together and mix well. Taste to make sure there is enough sugar for your taste.Fill the dough with enough of the filling mixture so that it is heaped high above the edge of the pan.
Place the pastry tops over the filling. Using a knife or a fork, seal the edges and decorate as you wish. Cut a small slit in the top. Glaze the tops with some milk.
Bake in the oven for 25-30 minutes.
Let them cool down until they are just warm and enjoy as is or with some homemade custard.