Steps
1. Preheat oven to 375°F (190°C).
2. Heat olive oil in a small skillet over medium heat. Sauté mushrooms until tender, about 3-4 minutes. Add spinach and cook until wilted, about 1 minute. Remove from heat.
3. In a bowl, whisk together egg, milk, salt, pepper, and garlic powder.
4. Place pie crust in a small tart or pie dish.
5. Spread sautéed mushrooms and spinach evenly over the crust.
6. Sprinkle shredded mozzarella on top.
7. Pour egg mixture over the fillings.
8. Bake for 20-25 minutes, or until the filling is set and the crust is golden brown.
9. Let cool for 5 minutes before serving.