Preheat the oven to 375 degrees.
Drizzle the olive oil into a nonstick skillet and heat over medium-high heat.
Add the chopped onion and cook for about 5 minutes, until soft and translucent.
Add the spinach to the skillet and stir for about 3 minutes, until any remaining moisture cooks off.
Remove from the heat and set aside.
Lightly coat a 9-inch nonstick pie pan with olive oil cooking spray.
Sprinkle the grated cheese evenly across the bottom of the pan.
Spoon the spinach and onion mixture over the cheese.
In a medium bowl, whisk together the egg whites, whole egg, cottage cheese, cayenne red pepper, sea salt, nutmeg, and black pepper.
Pour the egg mixture evenly over the spinach.
Bake for 40 to 45 minutes, or until the quiche is set in the center.
Let it sit for about 5 minutes before slicing into wedges