Finely chop the onion, garlic, then dice and peel the sweet potatoes. Cut the bell pepper into small slices, the carrots into small chunks.
Heat the oil in a saucepan, then gently sauté the onion and garlic. Add the spices and oregano, stir for a few seconds, then add the sweet potato, red pepper and carrot pieces.
Stir in the tomato purée. When the veggies are well coated, add the chopped tomatoes and chicken stock. Season with salt and pepper.
Bring to the boil. Cover, then simmer over low heat for 20 minutes or so.
Add the chicken pieces and the drained chickpeas, then warm through. If the stew has too much liquid, reduce it by turning up the heat for a few minutes.
Turn off the heat and mix in the chopped fresh coriander leaves. Transfer the stew into a deep pie dish – it can be square, oval or round shape. You can refrigerate it to bake the pie later.
Preheat the oven to 200°C.
Unroll the pastry. Put the pie dish onto it, and cut the pastry about 2 cm bigger than the dish. Put this cut-out piece on top of the dish, pressing the pastry around the edges to seal.
Use the remaining pastry to create decorations - leaves, flowers, letters or other motives. Press these onto to pastry with the beaten egg, if used.
Make a few incisions in the pastry to allow the steam to escape, then brush the pastry with the egg for a golden, crispy finish.
Bake for 20 minutes or until the pastry is golden and it has risen nicely.