Preheat the oven.

In a bowl, combine flour and salt.

Cut in butter until mixture resembles coarse crumbs.

Stir in ice water until dough forms.

Roll out the dough and place it in a baking dish.

In another bowl, mix turkey, Swiss cheese, spinach, mushrooms, onion, eggs, milk, black pepper, and garlic powder.

Pour the filling into the prepared crust.

Bake in the preheated oven until cooked through and golden.