Fill 4 highball glasses with crushed ice. Add 1 cucumber slice, 1 lemon slice and 2 strawberry halves to each glass.
Add the Pimm's, sparkling lemonade and the remaining cucumbers, lemons and strawberries to a pitcher. Add the basil. Stir until combined, then pour evenly amongst the glasses. Top each with a sprig of basil.
To make crushed ice, add regular ice cubes to a food processor and pulse until a finer snowy ice forms.