Preheat the oven to 350°F (175°C).

In a mixing bowl, combine finely chopped pistachios, crumbled feta, grated Parmesan, breadcrumbs, and melted butter. Mix until well coated and crumbly.

Press the crust mixture into the bottom of a springform pan and bake for 10 minutes until golden brown.

In a skillet, heat olive oil over medium heat. Add chopped mushrooms and minced garlic, sauté until soft, about 5-7 minutes. Let cool.

In a large bowl, cream the softened cream cheese until smooth. Add sour cream, eggs, and an extra sprinkle of Parmesan, blending until smooth.

Fold the cooled mushroom mixture into the cream cheese filling, seasoning with salt and pepper.

Pour the filling over the pre-baked crust, smoothing it out evenly.

Bake for 35-40 minutes until edges are set and center is slightly jiggly.

Cool in the pan for 10 minutes, then let it cool completely before removing the sides.

Garnish with fresh thyme and chopped pistachios before serving.