Preheat oven to 350 degrees F. Grease a 9-inch normal depth (not deep dish) pie pan with butter.
In a large skillet, heat the olive oil over medium-high heat. Sauté the shallots until they begin to soften (aproximately 1 ½ minutes).
Add the chopped fresh spinach and sauté until the spinach totally wilts (an additional 1 ½ aproximately). Remove from heat.
In a large mixing bowl whisk together the eggs, cream, salt, pepper and nutmeg. Stir in the Gruyere cheese, ham (or bacon; whichever is being used), spinach and shallots.
Pour into the prepared pie pan. Place in the oven for 20 minutes.
At 20 minutes sprinkle the shredded Parmesan cheese on top of the quiche and cook 10 additional minutes. Total cooking time will be between 30 and 35 minutes depending on your oven.
NOTE: The quiche will be slightly browned around the edges. It may be puffed up in the middle and may have a very slight jiggle in the middle. This is normal (it should not look uncooked, watery/soupy but may move very slightly when moved in the middle).
Remove and place the quiche on a wire rack to cool for 10-15 minutes before serving. The quiche will deflate and become a dense custard consistency.