To make the topping, boil the potatoes for 15 to 20 minutes until tender then drain, reserving the water. Mash with the ground and fresh coriander and yogurt.
While the potatoes are boiling, heat the oil in a large saucepan, add the ginger and fry briefly. Add the curry powder and garlic, stirring quickly as you don’t want it to burn, then tip in a can of chickpeas along with the water from the can. Stir well, then mash in the pan to smash the chickpeas up a bit. Tip in the second can of chickpeas with the water from the can and add the carrots, corn, bouillon and tomato purée. Simmer for 5 to 10 minutes, stirring in some of the potato water, if needed to loosen.
Heat the oven to 200C/180C fan/gas 6. Spoon the filling into four individual pie dishes (each about 10cm wide, 8cm deep / see Notes) and top with the mash, smoothing it to seal the filling inside. Bake for 25 minutes until golden. Wilt the spinach in a pan over a low to medium heat with a splash of water and some seasoning, then serve alongside the pie(s).
The pies will keep in the fridge for 4 days, or in the freezer for up to 3 months. To cook from frozen, bake for 40 to 45 minutes until golden and piping hot.