In a large wok melt the butter and add oil add the finely sliced chilli's and garlic, peppercorns, cardammon and spices. Stir-fry the diced chicken breasts in the mixture untill covered fully and starting to brown
Add the potato, onion and pepper all diced, stir fry for a further 5 mins
Add the coconut milk and stir in thoroughly, reduce heat and leave to simmer for 30 mins stirring occasionally, untill sauce is thickened
Add the yoghurt and stir in, remove from heat immediatley or yogurt will start to seperate.
Serve with naan, rice and your favourite indian chutneys