Preheat the oven to 400 degrees Fahrenheit.
Line the pie dish with all-butter pie crust and crimp. Using a fork, prick the bottom of the crust a few times to prevent any puffing when baked.
Blind bake the crust using pie weights according to your pie crust baking instructions. The crust should be golden brown in color. Set the baked crust aside for assembly.
Lightly grease a pan with olive oil. Add the chopped onion and cook until softened. Add the minced garlic and cook until it is golden in color.
Add the baby spinach into the pan and cook until the spinach has wilted and cooked thoroughly. Remove the pan from heat once the moisture from the spinach has fully evaporated.
Cook the bacon in the pan until browned. Remove and pat the excess fat off with a paper towel. Chop bacon into bite sized pieces.
In a bowl, mix the spinach, garlic, and onion mixture with the chopped bacon. Set aside.
In a separate bowl, whisk eggs, milk, salt, pepper, and nutmeg together. Set aside.