1/2cup(2 ounces) grated extra sharp white cheddar cheese
chives for garnish, optional
Preheat the oven to 350°F.
Spray a 9-inch pie plate with nonstick cooking spray. Peel sweet potatoes and slice very thinly – using a mandoline if possible. Layer sweet potatoes into pie plate, overlapping to completely cover the bottom of the pie plate. To create side of crust, trim the sweet potato slices so they are flat on one side and continue to line the edges of the pie plate, overlapping slices. Continue this process until the pie plate is completely covered (you want it 5-7 layers thick). Spray again with nonstick cooking spray or olive oil spray.
Bake sweet potato crust for 20 minutes at 350F°
Meanwhile, fry bacon pieces in a large skillet over medium heat until browned and crispy. Remove bacon pieces to a paper towel lined plate, reserving 1 tablespoon of bacon grease in pan. Keeping heat on medium, add onion to bacon grease and cook until translucent. Add spinach, cover for 1-2 minutes, and then stir until spinach is wilted.
Whisk eggs and milk in a bowl with salt and pepper until combined.
When crust is pre-baked, remove from oven, increase oven temperature to 400°F.
Carefully fill crust with spinach mixture. Sprinkle bacon on top of spinach and cheese on top of the bacon. Pour egg mixture over spinach, bacon and cheese. If you have too much egg mixture, discard (this will depend on the size of your pie plate and how deep you made your crust).
Bake at 400°F for 25 minutes or until eggs are set in the middle. Cool slightly (5 minutes) before slicing and serving.
For a crispy cheddar top crust, sprinkle more cheddar on the top of the quiche before baking.