Preheat oven to 425.Unroll pie dough into a deep dish pie pan, prick all over with fork.Prebake pie dough for 12 minutes, remove and set aside. Reduce oven temperature to 350.Whisk together eggs, salt, pepper and heavy cream; stir in cheese set asideIn a large skillet over medium heat, melt butter, add olive oil.Add mushrooms, cook until golden, about 8-10 minutes.Add garlic and cook for 30 seconds.Toss in spinach and cook until just wilted. Allow mixture to cool for about 10 minutes.Stir the vegetable mixture into the egg mixture and pour into pre baked pie crust.Place onto a rimmed cookie sheet and bake for 45-50 minutes or until set.Lightly cover with foil if crust is getting dark.