Preheat the oven to 375 F.
Grease a muffin tin, and lay the pie crust over the muffin tin, press the crust into the tin, and cut around the edges to form a muffin shape.
Cook the turkey bacon in a pan, and remove once cooked. Sauté the mushrooms in the same pan with the bacon grease until golden brown.
Use 1 cup of the gruyere cheese and sprinkle at the bottom of the pie crust.
Whisk together the eggs, milk, pepper, and garlic powder. Then, fold in the mushrooms, spinach, and green onions.
Pour the egg mixture evenly between each quiche, then sprinkle the remaining cheese on top.
Place the muffin tin in the oven, and bake for 20-25 minutes, until the tops are golden brown.
Let cool for 5 minutes then remove the quiches from the muffin tin. Enjoy!