Crush the ice in a blender at maximum speed, in 2 batches of ten seconds each.
Wash 3 lemons and cut off both ends. Then cut the lemons into four pieces and toss them in the blender.
Add in sugar and one liter of water.
In 3 batches, beat at maximum speed for 1 second.
With a strainer, pour the lemonade into a pitcher, add 250 ml of water, mint leaves and more ice to taste. And stir with a wooden spoon... Et voilà! Enjoy the summer!