Creating your Zucchini Mushroom Quiche is easy if you follow these simple steps:

1. Preheat Oven: Preheat your oven to 375°F (190°C).
2. Prepare Vegetables: In a skillet, heat a tablespoon of olive oil over medium heat. Add the diced onion and sauté until translucent.
3. Add Mushrooms: Add the sliced mushrooms to the skillet and cook for about 5 minutes until they are soft. Then, add the zucchini and cook for an additional 5 minutes. Season with thyme, salt, and pepper.
4. Mix Egg Mixture: In a medium bowl, whisk together the eggs and milk until well combined. Stir in the cheese and season with salt and pepper.
5. Combine Ingredients: Once the vegetables are cooked, spread them evenly over the pie crust. Pour the egg mixture over the vegetables, ensuring everything is well-distributed.
6. Bake the Quiche: Place the quiche in the preheated oven and bake for 35-40 minutes or until the center is set and the top is lightly golden.
7. Cool the Quiche: Remove the quiche from the oven and let it cool for about 10-15 minutes before slicing. This allows it to set further for cleaner slices.
8. Garnish: If desired, sprinkle fresh parsley on top for a pop of color and freshness.

By following these steps, you’ll create a delicious Zucchini Mushroom Quiche that is sure to impress.