Cucumber-Mint Spritzer

Slice cucumbers into thin ribbons or disks using a mandoline or vegetable peeler. Place in a pitcher. Add mint leaves and gently muddle. Squeeze juice from 1 1/2 lemons (or limes) into the pitcher, reserving the other half for garnish. Stir in seltzer. Serve over ice, garnished with mint sprigs and lemon (or lime) slices, if desired.