Preheat your oven to 375°F (190°C).

In a large mixing bowl, combine the chopped spinach, bell peppers, and zucchini. Sprinkle in garlic powder, onion powder, salt, and pepper.

In a separate bowl, whisk together the eggs and cheeses until smooth.

Fold the egg and cheese mixture into the prepared vegetables until well incorporated.

Pour the combined mixture into the greased casserole dish, smoothing out the top.

Place in the oven and bake for 30–40 minutes until golden brown.

Let cool for about 10 minutes before serving.