In a medium bowl, mix all the marinade ingredients with some seasoning. Chop the chicken into bite-sized pieces and toss with the marinade. Cover and chill in the fridge for 1 hr or overnight.

In a large, heavy saucepan, heat the butter, ghee or oil. Add the onion, garlic, green chilli, ginger and some seasoning. Fry on a medium heat for 10 mins or until soft.

Add the spices with the tomato purée, cook for a further 2 mins until fragrant, then add the stock and marinated chicken. Tip everything into the slow cooker, then cook for 6-7 hrs on Low until the chicken is tender.

Sprinkle with the toasted almonds. Serve with rice, naan bread, chutney, coriander and lime wedges, if you like.