1. Wash mint, dry and disassemble into leaves. Squeeze juice from one lemon, cut the second into thin circles. Lightly crush the mint leaves with sugar. 2. Put a few ice cubes and mint into a shaker, pour in lemon juice. Beat 3-4 sec. 3. Add tonic and beat for a few more seconds. Pour the cocktail into a pitcher filled with ice cubes. Put in lemon slices. Sugar can be added if desired.