Preheat oven to 400 degrees Fahrenheit.

In a sauté pan, heat olive oil, add onion and sauté until onions are just starting to turn golden. Add mushrooms and zucchini, then sauté for five minutes while stirring constantly.

In a bowl, combine eggs, mayonnaise, and spices. Add sauteed vegetables and mix gently yet well, until all combined. You want to keep the vegetables whole.

Add the mixture to the dish, sprinkle with some fresh parsley leaves, and place into the oven. Bake for for 30 minutes, then reduce the oven temperature to 350 degrees Fahrenheit and bake for an additional 15 minutes.