If using a hob, add all the ingredients for the chicken tikka to a large saucepan along with about ½ a can of water or enough that the chicken is mostly covered. Stir and simmer for 40 mins or until the chicken is cooked through. If using a slow cooker, add all the ingredients for the chicken tikka to a slow cooker (leave out the food colouring if you prefer) and cook on high for 4 hours or low for 6-7 hours.