Step 1

Preheat the oven to 425 degrees F (220 degrees C). Prick pie shell with a fork.

Step 2

Bake in the preheated oven until lightly golden, 6 to 8 minutes. Remove and let cool. Reduce oven temperature to 350 degrees F (175 degrees C).

Step 3

Bring a small pot of water to a boil. Add spinach and cook until heated through and dark green, about 5 minutes. Drain well and let cool.

Step 4

Combine Swiss cheese and flour in a bag. Seal and shake until cheese is coated.

Step 5

Whisk milk, eggs, salt, pepper, and nutmeg together in a large bowl. Stir in spinach and flour-coated Swiss cheese. Pour into the cooled pie shell.

Step 6

Bake in the preheated oven until middle is set, 50 to 60 minutes. Cool slightly before slicing and serving.