Distribute the lime juice, cucumber slices, and mint leaves (if using) evenly between two tall cocktail glasses. Using a muddler or the handle of a wooden spoon, muddle the cucumber slices and mint ...
Make sure that you are not pulverising them into a powder and just slightly crushing them into small pieces. Then, add these crushed spices to a saucepan, pour some water and grated (or sliced) ginger ...