Place the Flour and Salt in the bowl of your Food processor and mix to combine. Add the very cold Butter, cut into small cubes, and pulse until you get a thin crumb texture. Slowly add the cold Water while mixing until the dough starts to come together.

Assemble into a disk and transfer between two sheets of baking paper. Roll the Pastry into a large round, then place in the fridge to rest for at least 1 hour.

Take the pastry out of the fridge and leave at room temperature for about 5 minutes. Remove the baking paper and place inside a quiche pan.

Gently slide the pastry down the sides of the pan. Press on the bottom corners and the sides of the pan. Use a sharp knife to cut out any excess dough. Dock the bottom of the pastry.

Preheat your oven on 160 degree Celsius (325 degree Fahrenheit). Place the quiche pastry in the freezer. Cover with baking paper and fill with weights. Par-bake for 15 minutes. Remove the weights and baking paper and bake for another 10 to 15 minutes.

Wash and clean the Leek, then thinly chop it. Heat up a large saucepan with Olive Oil and add the minced garlic and leeks. Cook until the leeks are soft.

Brush or peel the mushrooms and cut into thin slices.

Place the Eggs, Cream, Salt, Pepper and Dried Herbs in a bowl and whisk until smooth. Add the Grated Cheese and whisk until combined.

Place the cooked Leeks and thinly sliced Mushrooms on the bottom of the pie crust.

Pour the egg mixture over the veggies. Optionally, top with remaining mushrooms, leeks, and cheese.

Bake for 40 to 50 minutes, or until the filling is fully baked. Leave to cool down slightly before serving.