In a stand mixer (the brave ones can do it by hand) add the flour, salt and then the frozen butter into cubes. Beat until the flour looks like wet sand.
Add the egg and the cold water and continue beating for one minute. Then continue by hand (it is good to wear a glove so that no heat passes into the dough) until the dough is formed.
Cover with a bee's wrap (not transparent plastic film, bee's warp, enough with the pastic) and let the dough rest in the refrigerator for at least one hour.
Dust a clean surface with some flour and by using a rolling pin roll out the dough (if you find it difficult leave the dough for 10 minutes to room temperature). After rolling out the dough and by using the rolling pin transfer the dough to a floured and buttered form.
Prick it with a fork, cover with baking paper and baking beans. Bake for 20 minutes on 190* C (preheated).
Remove the tart from the oven, remove the beans and paper, put back in the oven for extra 10-15 minutes until the pastry turns golden. Remove from the oven.