Separate the eggs, use the egg whites elsewhere. Place egg yolks and 100 g sugar in a high saucepan. Finely grate the zest of 1/2 lemon and add to the egg yolks. Add 1 liter of milk and mix briefly with a hand blender. 2.
Stir the cornstarch into the remaining milk until smooth. 3.
Heat the egg milk gently over low heat while stirring (preferably with a wooden spoon). Then add the cornstarch that has been stirred in. Heat the mixture over low heat, stirring constantly (now preferably with a whisk), until the maizena (cornstarch) binds the egg yolks and a thick cream is formed (caution: the cream must not make under any circumstances!).
Remove the saucepan from the stove and place it in a cold water bath to stop the cooking process and prevent the cream from curdling.
Divide the Crema catalana evenly among 6 suitable shallow bowls (e.g. special Spanish clay bowls) and cool completely.
To serve, preheat a branding iron well. Sprinkle each unit of crema evenly with about 1 tbsp. sugar. Hold the hot iron very close over or on the surface and caramelize the sugar. Serve immediately.
Only real with iron
The caramel on the authentic Crema catalana is made with a spiral iron, which is available in Spain for little money in any hardware store. A blowtorch offers only an imperfect substitute,