Preheat oven to 375 F.
In a large skillet, cook bacon (12 pieces) over medium heat.
Once cooked, remove from the pan to a paper towel-lined plate.
Add sliced mushrooms (3 cups) and diced onions (1/2) to the skillet, and cook in the bacon grease until onion is translucent (about 10 minutes).
Stir in fresh spinach (6 Oz) and continue to cook until spinach is wilted (you may need to do this in batches depending on the size of your pan).
Chop the bacon into bite sized pieces.
In a large bowl, whisk large eggs (6) with chopped fresh thyme (1 teaspoon), salt (1 teaspoon) and pepper (1/2 teaspoon).
Stir in cooked veggies, bacon, heavy cream (1 cup), and shredded swiss cheese (1 cup).
Pour filling into your baked crust.
Bake in the oven for 35-40 minutes, or until the center is firm and the edges begin to brown.
Allow quiche to cool before slicing, and enjoy!