Preheat oven to 350°F.
In a large mixing bowl, combine zucchini, tomato, onion, oregano, salt, pepper, ½ cup cheese, and baking mix.
In a separate bowl, whisk eggs with olive oil (or applesauce).
Add the egg mixture to the zucchini mixture and mix well.
Pour into a greased or parchment-lined baking dish.
Sprinkle the top with remaining cheese.
Bake for 55–60 minutes or until the top is golden and the casserole is firm in the center.
