Add the onions, chicken, garlic and ginger to the slow cooker pot.
Add the spice mix.
Add the chopped tomatoes, mango chutney and coconut milk.
Stir well and cook on low for 5-6 hours or on high for 3-4 hours.
15 minutes before the end, add the spinach and coriander.
If you want this curry to be spicier, then you can add extra cayenne or even add a sprinkle of red chilli flakes before serving.
We have used curry powder for the spices in this to keep it a super simple curry. However, you could use your favourite curry paste instead. It's a great way to make a different curry every time. You could have a korma or madras.
You can use chicken breast instead of thighs.
You could soften the onion and seal the chicken in a pan before adding it to the slow cooker, but I really don't think it is essential.
You can cut the chicken thighs into chunks, like we have, or leave them whole and once cooked use two forks and shred it all up and then give it a good stir.
If you want to cook this on the hob (stove top), then fry up the chicken, onion, garlic and ginger until the chicken is browned and then stir in the spices. Then add the tomatoes, mango chutney and coconut milk, stir and simmer for 40 minutes.
If your sauce ends up too thin, then you can add a cornflour (cornstarch) slurry to thicken it up.