First boil two peeled and chopped potatoes in a large pan until soft. Drain and set aside.
Pre-heat the oven to 180°C (fan)/200°C/gas mark 6.
Heat the oil in a frying pan and add 1 tsp cumin seeds and 1 tsp mustard seeds. When the mustard seeds start to pop add 1 chopped onion.
Reduce the heat, stir well and cook gently until the onion is soft.
Add 2 chopped cloves of garlic and a 1 inch piece of ginger, chopped, stir and cook for a further minute. Add 1/2 tsp turmeric, stir and cook well for a further minute.
Stir through the two cooked potatoes and 1/2 tin of chickpeas and mash well. Stir through 1/2 tbsp garam masala and chopped fresh coriander if using.
Allow the filling to cool slightly.
Unroll your sheet of puff pastry. Cut into six squares. Put a spoonful of potato mixture in the centre and fold over. Press the edges tightly together.
Brush the pastries with plant-based milk. This isn't essential but will help them to turn more golden brown in the oven.
Bake for 20-25 minutes until golden brown.