Whisk the egg yolks and 50 g sugar with the whisk of the hand mixer until thick and creamy. Mix 150 ml milk and starch until smooth and fold into the whipped egg yolk mixture.
Bring 600 ml milk, cinnamon stick and lemon peel to the boil. Remove the cinnamon stick. Stir hot milk into the egg yolk mixture.
Put the egg milk back into the pot and heat it over medium heat while stirring constantly until the starch binds and a thick cream is formed (must not boil!). Pour the cream into a bowl (preferably metal) and place in a cold water bath.
Let it cool down. Stir from time to time.
Divide Crema catalana into four flache bowls and sprinkle each with 1 tablespoon of sugar. Caramelize with a kitchen gas burner.