Add the ingredients for the marinade into a blender with 100ml water and blend to make a smooth paste, set aside.
In a large pan, add the oil over medium heat.
When the oil is hot, add the onion and cook for 4-5 minutes until lightly browned.
Add the tomatoes and cook for 3-4 minutes until softened.
Add the salt, turmeric, chilli powder, cumin powder, and chilli flakes and cook for 2-3 minutes.
Add the chicken pieces and cook for 4-5 minutes, stir frequently.
Once the chicken has changed colour, add the vindaloo paste and 200ml water and mix well.
Cover and cook on medium heat for 20 minutes, stirring occasionally.
Garnish with finely chopped coriander.
Serve with homemade rice or naan bread and enjoy!