For 6 people
Grate the lemon peel and remove the zest, then chop it. Split the lemon and squeeze the juice.
In a bowl, whisk the egg yolks and sugar. Add the cornstarch and mix. Stir in the lemon juice and zest.
Pour the milk into a saucepan and bring to a boil.
Pour the milk into the bowl and whisk until smooth and evenly mixed.
Put the mixture in the saucepan, cook for 2 to 3 minutes.
Pour the lemon pastry cream into a bowl and cover. Refrigerate before serving.