In a mixing bowl, combine flour and sugar. Cut in butter until mixture resembles coarse crumbs. Stir in egg yolk and cold water until dough forms. Press dough into a tart pan.
Bake crust for 15 minutes. Let cool.
In another bowl, whisk together sugar, eggs, lemon juice, lemon zest, and heavy cream. Pour into cooled crust.
Bake for 30 minutes or until filling is set. Let cool completely.