Cut out circles in the shortcrust pastry sheets using a small bowl or cookie cutter. The circles should be large enough to line your muffin tray, with a slight overhang. 1 sheet should amount to about 4 circles.
Line muffin tray with shortcrust pastry, allowing the edges to overhang slightly.
Divide the Butter Chicken mixture evenly among the pastry cases.
Cut out circles in the puff pastry sheets just large enough to top the pies, along with a bit of excess.
Brush the edges of the shortcrust pastry with a little egg, then top the pies with the puff pastry circles, pressing gently down to seal.
Using the tip of a fork, make indents around the edges of the puff pastry to help seal both layers further.
Brush the pies with the remaining egg. Cut a small cross in the centre of each pie so that steam can escape while baking.
Bake pies in oven for 30 minutes or until puffed and golden.