Place flour and butter in food processor. Pulse until butter is cut into flour.
Add egg and water. Pulse until a dough ball is formed. IF a ball is not forming, add a TINY amount of water until dough ball forms. Sometimes, I add too much water and it becomes sticky. No worries, just add a touch more flour.
Refrigerate for about 10-20 minutes.
On a floured surface, roll out dough to desired diameter. If too sticky, add a sprinkle of dough.