Line a pie dish with one sheet of shortcrust pastry. Bake in the preheated oven for 5 minutes. Sprinkle 55g Cheddar cheese into the pastry case and set aside.
In a bowl, combine the chicken, rice, black beans, sweetcorn, black olives, soured cream, salsa, Cheddar cheese, garlic granules and cumin. Season to taste with salt and pepper and pour the mixture into the pastry case. Top the pie with the remaining pastry sheet, seal the edges of the pie and cut slits into the top layer of pastry.
Bake for 25 minutes and check to see if the pastry is becoming too brown. If it is, wrap a strip of foil around the edge of the pie. Bake until the pie is golden brown and bubbling, 15 to 20 more minutes.
Allow the pie to sit for 10 minutes before serving.