Heat the butter and oil in a large saucepan. Add the chicken pieces and brown them all over. Remove from the saucepan and drain well on paper towels.
Add the golden shallots and onions to the saucepan and cook on medium heat for 5 minutes, or until soft. Mix in the curry powder and cook for 1 minute, then add the curry paste and flour and cook for 1 minute more.
Gradually pour in the stock and bring to the boil, stirring until thickened. Add the mango chutney, lemon juice and apples and mix well. Return the chicken to the saucepan, reduce the heat, cover and simmer on low heat for 30–40 minutes, or until the chicken is tender. Using a slotted spoon, remove the chicken pieces from the sauce and arrange them on a serving dish.
Pour the curry sauce into a food processor and blend until smooth. Return it to the saucepan, stir in the sultanas and cream and season to taste. Reheat the sauce gently, but do not boil or it will curdle. Pour over the chicken pieces and serve with hot cooked rice.