In a saucepan, heat olive oil over medium heat. Add mixed vegetables and mushrooms, sauté until tender.

Stir in vegetable broth, soy sauce, thyme, and garlic powder. Simmer for 10 minutes.

In a mixing bowl, combine flour and salt. Cut in vegan butter until mixture resembles coarse crumbs.

Add cold water gradually, mixing until dough forms. Roll out and fit into pie dish.

Pour the filling into the prepared crust. Cover with another layer of crust, sealing edges.

Cut slits in the top crust for steam to escape. Bake in a preheated oven at 375°F for 30-35 minutes.