Preheat the oven to 190°C.
Line the base and sides of a 7 inch springform cake tin with nonstick baking paper. Beat the low-fat cream cheese in a large mixing bowl using an electric hand held whisk until smooth and creamy, usually 2 minutes. Add the caster sugar and the plain flour and mix again for 1 minute. Add the vanilla extract and lemon juice and then the eggs and egg yolk, one at a time, beating between additions.
Add the low-fat sour cream and mix until smooth. Fold in the peach slices at this point. Pour into the lined tin and tap gently on the side to release any trapped air bubbles. Transfer to a baking sheet and bake for 10 minutes before reducing the temperature to 110°C. Bake for a further 20 minutes then turn off the oven and open the door, allowing the cheesecake to sit in the oven for 2 hours.
Remove from the oven once cool and chill for 2 hours. When ready to serve, release the cheesecake from the springform tin and sprinkle most of the grated chocolate evenly on the surface. Cut into portions using a hot, sharp knife. Transfer to serving plates and sprinkle a little more grated chocolate on top and around.