Draw four 6cm circles on baking parchment and lightly grease them with vegetable oil.
Heat granulated sugar, lemon juice, glucose, and 15ml boiling water in a heavy pan until dissolved.
Boil the syrup until it reaches 150°C on a sugar thermometer.
Dip the pan base into cold water briefly to stop the cooking process.
Spoon syrup into the parchment circles, insert sticks, and cover with more syrup.
Preheat the oven to 150°C.
Bake pared lemon peel on a tray for 15-20 minutes until dried and golden.
Blend the cooled dried peel until finely chopped.
Add caster sugar and citric acid to the blender and pulse to combine.
Serve the set lollipops with the prepared lemon sherbet.