Melt butter in the pan on medium heat and add the oil
Season the chicken with salt and pepper and place it in the pan
Fry it on both sides until golden brown
Add the chopped onion and saute it until soft and translucent.
Add the tomatoes and chilies and simmer the chicken for about 10 minutes.
Add the peanut butter to the pan. Mix well to coat the chicken.
Stir constantly to make a sauce. (Add water if needed)
Lower heat for about 5 minutes.
Taste for salt and pepper.
Serve over cooked rice