Caramelize your onion in a couple of tablespoons olive oil - saute the onions for quite a while until they start to turn a delicious brown color. When the onions are sufficiently caramelized, add a handful of chopped spinach and heat just until the spinach is wilted.
Sprinkle some goat cheese in the bottom of the prepared pie crust. Spread the spinach and onions evenly over the goat cheese. If you wish, you could add some shredded cheese of your choice - cheddar or swiss perhaps. Sprinkle a little bit of nutmeg over the veggies and a little kosher salt and fresh ground pepper.
Whisk 4 eggs in a large bowl. Add 2 cups of milk (or 1 cup of milk, 1 cup of cream). Stir together well. Pour over the spinach, onions, and goat cheese.
Put the quiche in a preheated 400 degree oven. Cook for 15 minutes. Reduce heat to 300 degrees and cook for another 30 minutes. I generally turn off the oven and let the quiche sit in the oven until I need it.
This tastes great warm after it sets for a bit or cold the next day! Enjoy!