Peal half the lemon and carefully remove the white inner part.
Put 3/4 of the milk in a pot" add the lemon skin and the cinnamon. Bring to boil, lrt it ool and reserve for 24 hours in the fridge.
NEXT DAY: sieve the milk and add the sugar and bring to boiling point once more.
Mix the egg yolks, the 1/4 of the milk and the cornstarch. Beat everything until there are no lumps.
Once the milk is boiling retire from the fire and add the yolk mixture. Stir well.
Brin to boil one more time stiring all the time. Let it boil for 1inute snd never stop stiring *the bottom will get burned if you stop.*
Pour into a tray and let it cool down. Reserve in the fridge and take it out 30-40 minutes before serving.