Preheat oven to 350 degrees. Grease a 9 x 13 baking pan or large casserole dish.
Grate your zucchini and onion over large holes, or cut into large chunks and combine with garlic and herbs in a food processor.
Process in batches until all are chopped into small pieces.
Combine all remaining ingredients in a very large bowl.
Mix until fully combined.
Pour the mixture into your greased pan. Bake for 45-60 minutes.
It will be browned on top and will puff up some when it is done. You can make this a day ahead. Make sure that your baking dish does not go straight from the fridge to the hot oven, because that could cause it to crack though. I usually let mine sit on the counter for an hour before baking it.