Place prepared apples in a pan with 50ml (2fl oz) water. Sprinkle with sugar, then cover and cook over a low heat for about 10 minutes, until the apples start to collapse. Remove from the heat, allow to cool and then stir in the lemon juice and the glucose.
Transfer the mixture to a shallow, freezer-proof dish and freeze for 2 hours, or until ice crystals have formed around the edge. Stir well to break up the ice then return to the freezer until it's firm, stirring occasionally. Alternatively, churn in an ice-cream machine for a smoother consistency.
While the sorbet is freezing, make the apple crisps. Preheat the oven to gas ¼, 110°C, fan 90°C. Line a baking tray with nonstick baking paper. Place the sugar in a pan with 50ml (2fl oz) water and cook over a low heat, stirring to dissolve the sugar. Increase the heat and boil for 2-3 minutes. Cool.
Cut the apples into wafer-thin slices (use a mandolin if you have one). Coat the slices in the syrup, then place on the lined tray. Bake for 1 hour. Remove and transfer to a wire rack. Place the rack on the tray and return to the oven for a further 1 hour. Allow to cool. Serve with the sorbet.
The crisps can be stored in an airtight container for up to 2 days.