Preheat your oven to 350°F (175°C).

In a large mixing bowl, combine chopped pistachios, crumbled feta, grated Parmesan, breadcrumbs, and melted butter, mixing until crumbly.

Press the crust mixture firmly into the bottom of a 9-inch springform pan.

Bake the crust for 10 minutes until golden brown, then set aside to cool.

In a skillet, sauté mushrooms and garlic in olive oil over medium heat until soft, about 5-7 minutes, then cool slightly.

Beat the softened cream cheese until smooth, then fold in sour cream, beaten eggs, and Parmesan until creamy.

Incorporate the sautéed mushrooms, seasoning with salt and pepper to taste.

Pour the creamy filling over the cooled crust and bake for 35 to 40 minutes until set.

Cool in the pan for at least 10 minutes, then garnish with fresh thyme and chopped pistachios before serving.