Preheat the oven to 400°F. Grease a 9” glass pie dish with room temperature butter.
Add the Parmesan cheese and gently shake the pie dish until you have a light, even coating across the bottom and sides. Set aside.
Place a medium skillet over medium heat and add the olive oil, onion, and ½ teaspoon of salt. Sauté for 2 minutes.
Add the mushrooms, spinach, and garlic cook for 3-4 minutes. Turn off the heat and set aside.
Carefully crack the eggs and transfer them into a large bowl.
Whisk in the milk, turmeric, black pepper, and remaining ½ teaspoon of salt.
Ladle the egg mixture into the reserved pie dish until it is half full.
Carefully add the reserved vegetable mixture to the dish.
Ladle the remaining egg mixture atop of vegetables.
Arrange the asparagus on top of the quiche.
Carefully place the quiche in the center of the oven and bake for 45-55 minutes, or until golden brown on top and an internal temperature of 165°F is reached.
Once your quiche has completely cooled you can cut it into 8 slices, place them into individual containers, and refrigerate for up to 7 days.
For even better storage use a vacuum sealer. You can store the quiche in the freezer for up to two months.To Thaw: You can either pull your quiche from the freezer and put it directly into the microwave for 2 minutes or you can pull your quiche from the freezer the night before you need it and place it in the refrigerator overnight and then place it in the microwave for 1 minute when you're ready to eat it.