• Preheat the oven to 355°F (180°C).

Prepare the Cashew Cream:

• After draining the soaked cashews, place them in a blender with water, nutritional yeast, white vinegar, and salt. Blend at high speed for 15 to 30 seconds until you achieve a smooth, creamy texture. Set the cashew cream aside in a small bowl.

Cook the Mushroom Filling:

• Melt the vegan butter in a non-stick skillet over medium heat. Add the minced garlic and sauté for 1 minute.
• Then, add the sliced mushrooms, stirring occasionally, and cook for 3 to 5 minutes until they soften. Season with soy sauce, dried rosemary, and black pepper, cooking for an additional minute. Remove from heat and stir in the prepared cashew cream.

Assemble the Tart:

• Grease a 7.5-inch tart pan lightly with oil or butter. Lay out the vegan pie crust in the tart pan, trimming any excess dough. Pierce the base and sides of the crust with a fork to prevent bubbling during baking.

Fill and Bake:

• Evenly spread the mushroom filling into the prepared pie crust. Bake for 35 to 40 minutes, or until the crust turns golden brown. If you are using a glass tart pan, check the bottom for a fully cooked crust.

Cool and Serve:

• Let the tart cool for a few minutes before slicing and serving. Enjoy as is, or pair it with a fresh green salad.