Soak quinoa in hot water for at least 20 minutes, or up to overnight.
While quinoa is soaking, prepare the white bean puree: add the beans and half the minced garlic cloves to a blender or food processor and puree until smooth.
Place 1/2 tablespoon butter over medium heat in a skillet. Add the rest of the garlic and fry for 1-2 minutes, until golden. Add the mushrooms and a pinch of salt and let cook, stirring occasionally, until golden brown. While mushrooms are cooking, use a vegetable peeler to slice the zucchini into thin ribbons. Once mushrooms are done, remove from pan, add another 1/2 tablespoon of butter, and add the zucchini along with a pinch of salt over medium-high heat. Fry for 2-3 minutes until just softened.
Drain the quinoa, add 2/3 cup of fresh water, salt, pepper, and additional herbs if using to a high-speed blender. Blend until smooth. Batter should be the consistency of thick pancake batter.
Heat 1/2 tablespoon olive oil in a medium skillet. Once hot, add enough quinoa batter to cover the bottom of the pan; swirl to coat. Let cook undisturbed until you can easily slide a spatula underneath and flip the flatbread over. Cook for another 3 minutes, until fully cooked.
To assemble, spread the white bean puree on the flatbread and top with mushrooms and zucchini. Enjoy immediately!