Work the flour, sugar, egg, and butter into a butter dough. Let the dough rest for at least 1 hour. Then, fill greased tartlet molds with a very thin layer and bake at 180°C for approximately 10 minutes. Remove from molds and let cool.

Melt the white chocolate in a double boiler and mix with sour cream to form a smooth cream. Place fruit jam into the tartlets, then add a layer of cream. Chill and decorate.