Preheat oven to 375°.
Prepare pie dishes: roll out pie dough and line the bottom and sides of (2) 9-inch pie dishes. Dock the bottom of the pie crust (poke holes with the tines of a fork). Trim crust edges and create fancy design around pie crust with a fork (optional). Place both pie dishes in the refrigerator until needed.
In a large skillet, heat olive oil and butter on medium heat.
Add shallots and garlic to skillet and sauté for 1-2 minutes. Add mushrooms and thyme, toss with shallots and garlic, and increase stove temperature to medium high. Sauté until mushrooms are tender, about 8 minutes.
Add spinach to skillet and sauté with mushrooms until wilted, 6-7 minutes. Season with salt and pepper, to taste. Set mixture aside to cool.
In a large mixing bowl, combine beaten eggs, cream of mushroom soup, parmesan cheese, and a pinch of salt and pepper.
Remove pie crusts from refrigerator. Divide cooled mushroom mixture between the two pie dishes. Pour egg mixture over both pies. Brush pie crust edges with egg wash.
Bake both quiches in the center of the oven for 35-40 minutes, or until eggs are firm and crust becomes brown and flaky. Cool before cutting into slices. Enjoy!