Mix all the ingredients for the chicken together in a bowl and chill in the fridge for half an hour
Heat the oil in a wok or flat non-stick pan and sautée the chicken until it starts to caramelise
Take the chicken out onto a plate
Add the butter to the oil in the pan and heat until the butter starts to foam, then add in sequence the kashmiri chilli powder, passata/tomato puree, honey and salt
As soon as the sauce comes to the boil reduce the heat, add the cream (or crème fraiche) and carefully stir in to create a rich emulsion on a low heat
Finally add the cooked chicken and reduce the sauce until it takes on a smooth consistency
Finish with kasoori methi, garam masala and chopped green chillies (if you want a kick!) to taste and serve with naan (or rice).