1. Set out a 10-inch tart pan that has a removable bottom.
2. In a large bowl, whisk flour and sugar. Using a pastry blender cut butter into flour until pea size crumbs form.
3. In a small bowl whisk yolk in water. Then pour over the flour mixture; tossing with a fork until the dough clumps.
4. Turn the dough out onto a work surface, and gently press and fold the dough into a ball. Press the ball into a disc, wrap in plastic and let the dough rest in the fridge for 30 minutes.
5. Once the dough is ready, roll out to approx. a 12-13 inch circle so it will fit into your 10-inch tart pan. Gently pick up the pastry and place it in the tart pan. Press the pastry down and cut off any overhang. Freeze the dough for 20 minutes.
6. Meanwhile preheat oven to 400˚F.
7. Place the frozen tart onto a baking sheet. Using a fork, prick the bottom of the dough all over.
8. Line the tart with foil or parchment paper and fill with pie weights or dried beans.
9. Bake in the bottom third of the oven for 10 minutes. Carefully, remove weights and foil; bake for another 8 minutes until golden. Let cool on a wire rack.

Lemon Filling: 

1. Using a double boiler (or large heatproof bowl over a saucepan of simmering water), whisk together eggs, egg yolk, sugar and lemon juice.
2. Cook, whisking often, until translucent and thick enough to mound on a spoon. approx. 10-15 minutes.
3. Remove from heat and stir in butter.
4. Pour or spoon lemon filling into the tart shell, smoothing the top. Or place plastic wrap directly on the surface and refrigerate until ready to use, refrigerate for up to 24 hours).
5. Bake in the bottom third of 325°F oven until the filling loses some shine and forms a thin skin, about 8-10 minutes.
6. Let cool on a wire rack. Refrigerate until cold and filling firms up, approx. 2 hours.
7. Top with whipped cream and sugared berries.