Chole ~ Cinnamon Chickpea Curry

One from the Prashad book here. I made it along with the Chicken Chettinad and Lila Dhania Baath, both found elsewhere on this blog.
Ingredients then:
3x 400g tins chickpeas, rinsed and drained
Sunflower oil
15g Coriander seeds
8cm cinnamon stick
6 dried kashmiri chillies
8 cloves
1 tsp black peppercorns
6 dried Indian bay leaves
2 tsp cumin seeds
1 medium onion, finely chopped
4cm root ginger, finely chopped, then pulped
2 cloves garlic, finely chopped, then pulped
2 tsp salt
1 tsp Kashmiri chilli powder
1 tsp turmeric
1 tsp sugar (I used palm sugar but jaggery or dark brown sugar also fine)
2 handfuls freshly chopped coriander

Method:
Place the chickpeas along with 500ml water in a pan over a high heat, bring to the boil for 5 mins, then remove from heat and set aside (do not drain)
heat 4 tsp oil in a pan over a low heat, add coriander seeds, cinnamon, dried Kashmiri chillies, cloves, peppercorns, bay leaves and 1 tsp of the cumin seeds. Fry for 5 mins or so, stirring continuously. Set aside to cool.
Heat about 75ml oil in a large pan over a medium heat, add the other tsp cumin seeds and fry until they start to go brown (about a minute tops - make sure you don't let them burn)
Stir in the onions and fry until dark brown, stirring every minute or so.
Stir in the tomatoes, ginger and garlic, salt, chilli powder, turmeric and sugar and increase the heat to high.
Immediately stir in the chickpeas along with their cooking water and an additional 300ml warm water. Cover the pan and leave to simmer for 5 mins, stirring occasionally.
While this is going on, finely grind the cooled roasted spices. Note well: ensure you do not scrimp on this process unless you like pieces of cinnamon bark!
Add to the chickpeas, stir, then remove the pan from the heat.
Sprinkle with chopped coriander then cover the pan and leave to rest for around 10 mins.
Reheat over a medium heat to serve.