Pre-bake the pie crust: Preheat oven to 350°F. If using a homemade pie crust shell, freeze it for at least 30 minutes, then line the inside with heavy aluminum foil, pressing it against the sides. Fill with pie weights—dry beans, dry rice, or sugar work well.
Bake for 40 minutes.
If using a store-bought frozen pie crust, preheat the oven to 375°F. Thaw the crust for 15 minutes at room temperature. Poke the bottom and sides of the pie crust all around with the tines of a fork.
Place an empty pie pan of the same size inside the crust OR line the inside with heavy aluminum foil, and fill with pie weights—dry beans or rice work well.
Bake the pie shell on a baking sheet in the center of the oven for 12 minutes, or until it just barely starts to brown.
Remove from oven and let cool.
Sauté mushrooms, garlic: In a large sauté pan melt butter on medium heat.
Add mushrooms, stir to coat with the butter. Increase the heat to high, stirring constantly until the moisture the mushrooms has released and evaporated, a few minutes.
Lower heat to medium, add minced garlic, stir with the mushrooms for 30 seconds then remove from heat.
Make cheese egg filling: Beat together the eggs, sour cream, milk, and cream.
Add freshly ground pepper, a pinch of salt, and cardamom or nutmeg if using. Stir in the grated cheese and chopped parsley.
Spread the sautéed mushrooms along the bottom of the pre-baked pie crust.
Pour the cheese and cream mixture over the top of the mushrooms.
Bake at 350°F for 30-35 minutes, until lightly browned on top and a tester inserted into the middle comes out clean. If you find the crust edges getting too browned, put some foil around the top of them or use a pie protector.
Remove from oven and let cool for 10 minutes before serving.
