Make filling: Saute onions, mushrooms, and celery with butter in a skillet until tender. Stir in cauliflower and cook for 5 minutes. Add chicken, cream, broth, cream cheese, garlic powder and thyme; mix well. Simmer until creamy and thickened.
Prepare the crust: In a bowl, combine almond flour, coconut flour, baking powder, salt, egg, melted butter and cheese until dough comes together.
To make & Assemble: Pour the filling into a pie dish or small ramekins. Roll out the crust and put it in place.
Bake: Bake 180C (350F) for 20-25 minutes or until it is golden in colour.
Rest & serve: Allow the pie to cool for at least 10 minutes before serving.