Spinach Mushroom Sun-Dried Tomato Quiche [oil-free, dairy-free, gluten-free, vegan]

NOTE: This quiche can be made a day or two ahead and warmed up in the oven at 350 degrees F or in the microwave.

Crust:
1 tablespoon ground flax + 3 tablespoons water, mixed together
1 cup almond flour
1 cup oat flour (gluten-free if desired)
1 teaspoon dried oregano
1/2 t salt
1-2 T water

Filling:
1 block (14-oz) firm tofu, drained and pressed
1 medium onion, diced finely
3 cloves garlic, crushed
8 oz. cremini mushrooms, sliced
1/2 cup fresh basil leaves, finely chopped
1/4 cup sun-dried tomatoes, chopped and soaked in water for 30 minutes
3 handfuls of baby spinach, chopped
2 T nutritional yeast
1 t dried oregano
3/4-1 t salt (or less if desired)
a few shakes of black pepper

Preheat oven to 350 degrees F. 

For the crust: Mix together flax and water mixture in a small bowl and set aside. In a large bowl, stir together the almond flour, oat flour, oregano, and salt. Add in the flaxseed mixture and 2 T of water. Stir well. The dough will be somewhat crumbly, but it should stick together when you press it between your fingers.

Crumble the dough evenly over the base of a 9" pie dish. Press the mixture evenly into the pan, working your way outward and up the sides of the pan. Bake the crust at 350F for 15 minutes, or until lightly golden and firm to touch. Remove from the oven and set aside to cool while you finish preparing the filling. Increase oven temperature to 375F.

For the filling: Break apart the tofu block into 4 pieces and add into food processor. Process the tofu until smooth and creamy. If it doesn't get creamy, add a tiny splash of unsweetened non-dairy milk to help it along. Set aside.

In a large skillet, steamfry onion over medium-high heat with a little water until tender and translucent. Stir in the garlic, mushrooms, season with a few dashes of salt, and cook on medium-high heat until most of the water cooks off the mushrooms, about 10-12 minutes. Stir in the herbs, spinach, sun-dried tomatoes, nutritional yeast, oregano, salt, and pepper until combined. Cook until the spinach is wilted. 

Finally, remove from heat and stir in the processed tofu until thoroughly combined. Adjust seasoning to taste if desired. Spoon mixture into baked crust and smooth out with a spoon until even.

Bake quiche, uncovered, at 375F for 35 minutes, or until the quiche is firm to the touch. For best results, cool the quiche for 15-20 minutes on a cooling rack before attempting to slice.