Cut butter into flour. Add the whisked egg, vinegar and salt. Form it into a dough. Refrigerate for at least an hour.Roll the dough into a circle and set it on a pie pan. Bake for about 15 minutes at 180C. Set aside and let cool.
Using electric mixer, combine yolks and sugar until light and fluffy. And corn starch and combine. Heat the milk with a vanilla pod (with a line scored down the side). As soon as it starts to boil, pour the milk onto the egg mixture, whisking continuouslyTransfer to a skillet and cook over low heat until the cream thickens. Set aside and let cool.
Place the cream over the crust. Top with seasonal fruit: red and black currants, gooseberries and blueberries.