Heat oven to 220C/200C fan/gas 7. Pour 1 tbsp oil into a flameproof casserole dish. Addthe chicken, season and fry for 4-5 mins on a medium heat, turning, until lightly browned. Remove with tongs and set aside.
Pour another ½ tbsp oil into the casserole dish and add the spring onions. Fry gently for a couple of mins, then stir in the garlic, ginger and curry powder. Cook for 1 min, then tip the chicken back into the pan, along with the broccoli, soy sauce, coconut milk, chicken stock and cornflour mixture. Bring to the boil, then stir in the kale. Once the kale has wilted, take the dish off the heat.
Mix the remaining oil with the splash of coconut milk. Unravel the pastry. Brush each sheet lightly with the oil mixture, then scrunch up and sit on top of the pie mixture. Scatter over the nigella seeds, then cook in the oven for 12 mins, or until the pastry is a deep golden brown. Leave to stand for a couple of mins before serving.