880 gm(4 cups) caster sugar100 gmginger, finely grated3mint sprigs, plus extra to serve2Lebanese cucumbers, seeds removed, plus extra, thinly sliced, to serveJuiceof 2 limes, plus extra, sliced, to serveTo serve:chilled ginger beerTo serve:Pimms, optional
Combine sugar and 750ml water in a saucepan, stir over medium-high heat until sugar dissolves. Add ginger and mint, bring to the boil, reduce heat to medium and simmer until infused and a light syrup forms (8-10 minutes), remove from heat.
Meanwhile, process cucumber in a food processor until finely chopped, add to syrup and refrigerate until cool. Strain through a fine sieve, pressing on solids to extract liquid (discard solids), add lime juice, then refrigerate until required. Makes about 1 litre.
To serve, pour chilled syrup into glasses, top up with ginger beer to taste, and garnish with cucumber ribbons, lime slices and mint sprigs.