Preheat the oven to 375ºF.
Cut the zucchini in half, then quarter lengthwise. Chop into 1/2" pieces. (This doesn't have to be perfect, since you will be smashing them up later!) Finely chop the white onion.
In a large skillet over medium heat, sauté the zucchini, onion, and minced garlic in ghee until soft (about 15 minutes or more).
Transfer your softened veggies to a large bowl, and smash up the zucchini with a fork, or fancy mashing tool, until you have a "mash" consistency with some intact pieces. (Not an exact science... just whatever texture looks most appealing to you)
Stir in the remaining ingredients (almond flour, coconut flour, eggs, and spices) until combined.
Transfer your mixture to a greased 8" x 8" baking dish, cover with foil, and bake for 30 minutes. Remove the foil, and bake for an additional 20-25 minutes, or until the top is golden brown and "set" or doesn't jiggle when you shake the dish.
Let cool for 5 minutes, then slice & serve hot!