Wilt the spinach by adding it to a colander and pouring a kettleful of boiling water over it. Refresh with cold water, then squeeze most of the water out. Whizz in a food processor with the coriander until smooth.
In a large pan, heat the oil and add the spices.
Let them sizzle for a minute or two before adding the onion, garlic and chilli.
Saute the onions until soft.
Add the potatoes to the pan and coat in the spices, then add the spinach and allow to cook for 10 minutes until all the flavours have developed.