In a large bowl, mix the flour and salt.

Cut the vegan butter into the flour using a pastry cutter or your hands until the mixture resembles coarse crumbs.

Gradually add the ice water, one tablespoon at a time, mixing until the dough comes together.

Form the dough into a disk, wrap it in plastic, and chill for at least 30 minutes.

Crumble the tofu into a food processor. Add the plant-based yogurt, nutritional yeast, lemon juice, garlic powder, onion powder, salt, and nutmeg.

Blend until smooth and creamy, then set aside.

Heat olive oil in a skillet over medium heat.

Sauté the onion until translucent, about 5 minutes.

Add the garlic and cook for another minute.

Stir in the spinach, season with salt and pepper, and cook until wilted. Remove from heat and let it cool slightly.

In a bowl, whisk together the chickpea flour, water, olive oil, turmeric, and black salt until smooth. Set aside.

Preheat the oven to 375°F (190°C).

Roll out the chilled crust and press it into a 9-inch pie pan. Trim any excess dough and poke holes in the bottom with a fork. Prebake for 10 minutes, then set aside.

In a large mixing bowl, combine the sautéed spinach and onions with the vegan ricotta. Mix well.

Spread the spinach-ricotta mixture evenly over the prebaked crust.

Pour the vegan egg mixture on top, ensuring it fills all the gaps.

Bake the quiche in the preheated oven for 35-40 minutes, or until the filling is set and the top is golden.

Let it cool for at least 10 minutes before slicing to allow the quiche to firm up.