Finely grate the lemon zest.
Halve the lemons and squeeze the juice.
Place the lemon juice, zest and 150ml water in a pan. Add the sugar and bring to the boil, stirring. Boil for a few minutes until the sugar has dissolved.
Strain the lemon syrup through a fine sieve and allow to cool to room temperature.
Freeze for 5 hours. After 2 hours, whisk the ice thoroughly with a fork and repeat every 20 minutes until the ice is firm.
Scoop out portions of sorbet to serve.
If the sorbet is too hard to scoop, mix in portions with a blender until creamy. Place in small bowls and serve with strawberries marinated in icing sugar and balsamic vinegar.