Saute onion and garlic. Heat coconut oil in a large saucepan on medium high heat. Add onion and garlic, cook, stirring frequently for approximately 3-4 minutes or until the onions have become translucent.
Prepare sauce. Add coconut cream, chicken stock, tomato paste, tapioca, ginger, turmeric, garam masala, cumin, coriander, chili flakes and stirr until well combined and the sauce has started to thicken. Season with salt and pepper.
Cook. Add the chicken to the slow cooker, then add the sauce and mix through the chicken. Cover and cook on low heat for 5 hours.
Serve. Serve with the coriander and your favourite side (eg rice, quinoa, green vegetables)