Combine flour, butter and sugar in a food processor until crumbly. Add cold water gradually until the dough holds together.
Shape into a disk, wrap in plastic, and refrigerate for 30 minutes.
Roll out the dough, press into a tart pan, prick with a fork, and bake at 375F (190C) for 15-18 minutes until golden.
Whisk together sugar, eggs, lemon juice, zest and heavy cream until smooth.
Pour the lemon mixture into the cooled crust.
Bake at 325F (160C) for 20-25 minutes, r until the filing is just set with a slight jiggle in the center.
Let it cool completely then chill for 1-2 hours. Dust with powdered sugar or garnish with berries f desired.