Chicken, Leek, and Cheese Quiche

In a large bowl, combine the flour and salt.
Add the cold butter pieces and rub it into the flour with your fingers until the mixture resembles coarse breadcrumbs.
Add the egg yolk and cold water. Mix until a dough forms.
Shape the dough into a ball, wrap it in plastic film, and refrigerate for 30 minutes.
Prepare the Filling:

Heat the olive oil in a frying pan over medium heat.
Add the leeks and cook for about 5-7 minutes until softened and tender.
Stir in the cooked chicken, season with salt and pepper, and mix well. Let the filling cool down.
Assemble the Quiche:

Preheat the oven to 180°C (350°F).
On a floured surface, roll out the dough and fit it into a 28 cm (11-inch) pie dish.
Spread the chicken and leek mixture evenly over the pastry.
In a bowl, whisk the eggs, cream, and milk together. Season with salt and pepper, and pour the mixture over the filling.
Sprinkle the grated cheese on top.
Bake the Quiche:

Bake in the preheated oven for 35-40 minutes, or until the quiche is golden brown and the center is set.
Serving and Storage Tips: