Lemon Ice

As I bake slowly from one of the summer heat waves in Athens, I dream of Spain and a refreshing ice I used to eat there. I think it was called "limon granizzato" (my Spanish spelling might be off) and I don't know how it was made. This is my attempt to recreate the memory ...

Ingredients
4 servings

• 2 lemons
• 1/3 cup of icing sugar
• 2 cups of ice

Utensil note
You will need some sort of utensil to crush the ice: either an ice crusher, or a stainless steel blender or a pestle and mortar.

Preparation

Grate thinly the lemon peel from half of one lemon (the yellow part only, not the white one which is bitter). Squeeze the juice of the lemons.
Crush the ice and mix with the rind, juice and sugar.
The result should have a slushy consistency and a pale yellow color.
Eat immediately, either with a spoon from a bowl, or with a straw from a glass. Small sips, if you don't want your insides to freeze ...
It keeps in the freezing compartment of your refrigerator, but tends to harden over time.
You can freeze in an ice tray to make some very refreshing ice-cubes.
Notes
I use icing sugar, because it is very hard - if not impossible, to dissolve regular sugar in lemon juice and I hate finding all the sugar bits in my ice.
Just for the record, I have broken a blender the third time I tried to crush ice. (for some reason, it had no problem the two first times).
You can use more or less sugar, according to your taste, and more or less ice, depending on how strong you want it to taste.