Peel the cooled potatoes and cut into 1cm cubes. Heat a drizzle of rapeseed oil in a frying pan, add the ginger, green chilli and all the dry spices and cook for 1 minute. Add the cubed potatoes and cook for 3-4 minutes, tossing with the spices in the pan. Add the chopped coriander, peas and 1 tsp salt, and keep cooking for 2-3 minutes on a low heat. The veg should be well coated with spices. Check the seasoning and add a pinch of salt if you like. Remove from heat and cool.