Grate the rind of one lemon and squeeze the juice out of all of them.
Heat up 500ml of water with the cinnamon stick and the sugar, and once it starts to boil, let it simmer for 10 minutes. Let it cool.
Once cool, put in a bowl and add the lemon juice and the grated rind. Stir well and put the bowl in the freezer.
When the mixture is starting to freeze, beat the egg whites until they are stiff, adding the pinch of salt.
Take the bowl out and mix the eggs into the freezing mixture.
Put the bowl into the freezer until it is cold and hard.
Remove from the freezer 20 minutes before serving.
Key Ingredients: lemon, cinnamon, sugar, egg, lemon rind, salt