1) Heat the oil and fry the noisettes and onion for 4-5 minutes. 2) Add the apple juice, the sliced apple and cider and cook for 6-8 minutes until reduced. 3) Blend the cornflour with 2 teaspoons of water and add to the pan. Stir continuously for 2-3 minutes. 4) Remove pan from the heat and stir in the soured cream. 5) Return to a low heat and season to taste. 6) Sprinkle with chopped parsley before serving.