In a medium bowl, whisk the eggs, Parmesan cheese, sea salt, and black pepper. Set aside.

In a large skillet, heat the avocado oil over medium heat. Add the onion and cook for 3 minutes, stirring occasionally, or until softened.

Add the spinach leaves to the skillet. Cook, stirring, just until the spinach begins to wilt. Pour the egg mixture into the skillet. Cook, pushing the eggs back and forth with a rubber spatula, until the eggs are set.

Sprinkle with the sesame seeds and serve immediately.