1. Preheat oven to 350°F. Line a 9-inch ceramic or glass tart or pie plate with pie crust, working crust up sides with fingers and refrigerate until needed. In bowl, lightly whisk eggs and stir in half and half, Parmesan, salt and pepper and reserve.
2. In skillet, cook bacon over medium heat for 5-6 minutes or until slightly rendered and beginning to curl. Remove bacon from pan and drain on paper towels until cool enough to handle. Drain all but about 1 tablespoon fat from pan and cook mushrooms over high heat for 4-5 minutes or until softened and any moisture in pan has evaporated, stirring occasionally. Add in spinach leaves and cook for 1 minute or until just wilted.
3. Add mushrooms and spinach to egg mixture and stir to combine. Pour into pie crust and bake for 20-25 minutes or until eggs are just beginning to set. Increase oven temperature to 400°F. Arrange bacon loosely in woven lattice form on top of pie and return to oven, baking for 18-20 minutes or until bacon has begun to crisp and crust is golden brown. Let cool on wire rack for 10-15 minutes before serving.
Try some other mushroom varieties or another cheese such as Cheddar or smoked Gouda for a change of pace. Baby kale would be a great alternate leafy green as well!