Heat the oil in a pan on a medium heat and then add the onion, garlic, ginger and spices. Cook until they become translucent. Around 6-7 minutes.
Stir in the prawns, making sure they all get coated in the spices then pour in the coconut milk, juice of 1/2 lime and the mango chunks. Simmer for 5 - 10 minutes. A few minutes before the end of cooking, add in the cooked chicken and baby spinach. Stir to make sure it's all fully incorporated.
Serve with naan bread and rice.
Notes
If you don't have leftover chicken, you can easily pan-fry some chicken breasts and add them.