Steps
1. Heat the olive oil in a small non-stick pan on medium heat
2. Saute the mushrooms until tender
3. In a bowl, whisk together the eggs, cheese, spinach, mushrooms and seasonings and pour the mixture into the pan.
4. Cook until the bottom of the omelet is firm and lightly browned.
5. Flip the omelet carefully, and cook until the other side is firm.
6. Serve immediately.