Spray a frying pan with low-calorie cooking spray and set on a medium heat. Add the onions and fry for 4 minutes. Then add the pepper and garlic, and continue to fry for a further 4 minutes.
Add the chicken and cook for 6-8 minutes, until browned on all sides. In a small bowl, combine the cumin, coriander, chilli, garlic, and paprika. Sprinkle over the chicken and vegetables, then stir to coat.
Add the black beans, passata, tomato puree, and water. Then lower the heat and simmer for 5 minutes, until thickened.
Remove from the heat and stir through the cream cheese. Season with salt and pepper to taste. Pour into the ovenproof dish, and leave to cool slightly.
Preheat the oven to 180ºC.
Lay the pastry sheet on-top of the pie filling, and crimp and decorate the top. Brush with milk, then pop into the oven for 30 minutes — until the pastry is golden brown.