Preheat the oven to 375°F and grease an 8x8 glass baking dish.
Heat the olive oil in a skillet and add the red onion. Sauté over medium heat.
Meanwhile, squeeze the excess water out of the zucchini using a cheesecloth. Let it drain while you assemble the other parts.
Add the garlic to the pan and sauté for another five minutes.
Whisk the eggs together in a large bowl. Add 1 cup Parmesan, chives, and grated zucchini, and stir to combine. Add the onions from the pan to the bowl. Stir in the baking soda, salt, and pepper.
Top with remaining grated Parmesan.
Bake for 45 minutes until golden on top. Let cool and slice into squares to serve.
