For the custard
Pour the milk into a saucepan together with the sugar, the lemon peel and the cinnamon stick.
When it comes to the boil, lower the heat and simmer.
Add the beaten egg yolks and continue stirring until the mixture thickens.
Remove from the heat and when lukewarm fill the dessert glasses with it, adding a biscuit in each one.
Place the glasses in the fridge.
For the meringue
Whip the egg whites with the sugar and set aside.
Assembly of the dessert
Put a little whipped meringue on top of the custards and decorate with the sprigs of spearmint.