1. 1. Preheat your oven to 190°C (375°F).

2. 2. In a food processor, pulse together the all-purpose flour, whole wheat flour, and salt. Add the cold cubed butter and pulse until the mixture resembles coarse crumbs.

3. 3. Gradually add the cold water, pulsing until the dough just comes together. Be careful not to overmix.

4. 4. On a lightly floured surface, roll out the dough until it's about 3 mm (1/8 inch) thick.

5. 5. Carefully transfer the dough to a 23 cm (9-inch) pie dish and trim the edges to fit snugly. Refrigerate while you prepare the filling.

6. 6. In a skillet over medium heat, sauté the wild mushrooms in a small amount of butter until soft and aromatic, about 5-7 minutes. Season with salt, pepper, and fresh thyme or parsley. Let cool slightly.

7. 7. In a bowl, mix together the grated Parmesan and aged cheddar cheese.

8. 8. Spread the sautéed mushrooms evenly over the bottom of the chilled pie crust, leaving a 2.5 cm (1-inch) border around the edge.

9. 9. Sprinkle the cheese mixture evenly over the mushrooms.

10. 10. Fold the edges of the dough over the filling, pressing gently to seal. Brush the top of the crust with a little cold water and cut 2 or 3 small slits to let steam escape.

11. 11. Bake the pie for 35 to 40 minutes, or until the crust is golden brown and the filling is hot and bubbly. If the edges brown too quickly, cover them with aluminum foil.

12. 12. Let the pie cool for 5-10 minutes before slicing. Serve warm and enjoy!