For the potato and leek quiche, put all the ingredients of the dough in a bowl, mix with the dough hook of the mixer until the dough separates from the edge of the bowl, cover and let rest for 30 minutes.
In a large saucepan, bring 1 l of water to a boil along with the potatoes, cover, turn off heat (electric stove) and cook until tender, about 15 to 20 minutes (depending on potato size). Strain, peel potatoes and mash with potato masher.
Fry turkey ham cut into small cubes in olive oil all around, fry thinly sliced leek as well and add the mixture to the potatoes. Add sour cream (sour cream), egg and egg yolk, season with salt and pepper.
Roll out half of the dough and place in a quiche mold (diameter about 24 cm). Form the remaining dough into a roll (about 70 cm long), place in the mold at the edge and pull up the edge with your fingers. Pour in the filling, smooth it out and bake the potato and leek quiche in a preheated oven at 180 degrees for 45 minutes.