First make the filling:
Thinly slice the onion, then chop the garlic. Cut the carrot and red pepper into small cubes.
Heat the oil in a frying pan and gently cook the onion, red pepper, carrot and garlic for 5 minutes.
Add the tomato purée and oregano. Season with salt and pepper, then stir for a minute.
Add the chopped tomatoes and, using the tin, add a cupful of water. Bring to the boil then cook for 15 minutes.
Add the chickpeas and the kale. Cook for another 5 minutes.
Add the shredded chicken pieces. Stir for a couple of minutes. You should get a thick sauce - it should be stew-like. If it is not, turn up the heat and reduce it.
Take the pan off the stove, put the lid on to keep warm.
Set the oven temperature to 180°C. Grease a circular or square pie tin.
Unroll the pastry on a large chopping board.
Choose a plate which is about the size of the base of your tin plus the side. Put this plate on top of the pastry and using a knife, cut around it. Make a ball of the leftover pastry and put it back to a fridge.
Put the cut-out pastry in the base of the pie tin.
Fill the pastry base with the chicken and chickpeas filling.
Roll out the leftover pastry. Using a plate (a little bit bigger than the diameter of the top of the pie tin), cut out another circular shape. Place this on top of the pie, letting the edge overhang.
Pinch the top and base pastry together around the edge. Cut a slit on the top to allow the steam to escape, then brush with the egg.
Bake for about 20 minutes, until the pastry looks golden.
Let it cool for a few minutes, then carefully remove the pie from the tin onto a plate.
Cut it into wedges and serve.