To scoop out the lemons
Cut a 2 cm lid off the top of each lemon.
Carefully loosen the flesh from the lemons using a knife, empty into a bowl. Cover and freeze the lemon skins and lids for approx. 4 hrs. or overnight.
Mash the flesh with a fork, pass through a sieve into a measuring cup (produces approx. 100 ml of juice).
Bring the water and sugar to the boil in a pan, then reduce the heat and simmer for approx. 2 mins., leave to cool.
Grate the lemon zest and squeeze out the juice. Finely grate the ginger, add the lemon zest and juice to the syrup along with the ginger and reserved lemon juice.
Pour the lemon syrup into a wide stainless steel bowl, freeze the mixture for approx. 3 hrs., stirring thoroughly 4 times.
Transfer the sorbet to the frozen lemon skins, freeze for a further 2 hrs. Serve with the lemon lids.