Caramelized Onion + Mushroom Quiche

By Ashley Melillo of Blissful Basil

Eggs bring several not-so-easy-to-substitute qualities to the table because of their unique texture, protein content, sulfuric flavor, and binding capabilities.

This is especially true when it comes to meals that feature eggs as their shining star. Dishes like souffleés, custards, and quiches are inherently some of the more challenging ones to veganize due to their egg-laden nature. In recipes like these, eggs serve to bind, lift, and provide overall structure. Triple-threat status achieved.

But with a burgeoning and widespread acceptance of vegan foods has come game-changing creativity, too. So…challenge accepted, eggs.

While we certainly aren’t the first to feature a combination of tofu, chickpea flour, and kala namak to create a vegan quiche that’s highly reminiscent of its egg-filled predecessor, we’re sending our gratitude to whomever was.

A simple gluten-free crust is made with a combination of nut meal (of sunflower meal for our nut-free friends), oat flour, seasonings, a flax egg, and olive oil. 

The combination yields a crisp, nutty, and wholesome crust that packs a punch of fiber, anti-inflammatory omega-3 fatty acids, and vitamin e.

The quiche filling, as hinted at above, relies on a combination of extra firm tofu, chickpea flour, and kala namak to create an egg-like base. The tofu offers protein and texture, the chickpea flour adds lift, and the kala namak (i.e., black salt) imparts an egg-like sulfuric taste. You can substitute regular salt for the kala namak in a pinch, but black salt is a worthwhile ingredient to seek out if you plan to make vegan versions of egg-filled dishes with any regularity.

For the veggies, we went with a combination that hints at fall—caramelized onions and mushrooms. Fun fact: Onions and mushrooms are immune-boosting superstars in the plant world, appreciated for both their antibacterial and antiviral properties.

If you’re not up for mushrooms and onions, know that other vegetable combinations will work well, too. For a more colorful combo, we like to use a mix of finely chopped broccoli, bell peppers, and baby spinach. If you’re not needing to develop a rich caramelization on the veggies (as is the case for the former), you can simply give them a quick three-minute sauté in olive oil. No need to carry on for any longer than that, because they’ll continue to cook in the oven.

No matter which vegetables you opt for, the resulting quiche is one that’s savory, satisfying, and nourishing at both the macro and micro level. We hope you love this one as much as we do!

Nutty Oat Crust

• 1 1/2 tablespoons ground flaxseed

• 4 1/2 tablespoons filtered water, divided

• 1 1/2 cups almond meal, hazelnut meal, or sunflower meal (for nut-free)

• 1 cup oat flour

• 3/4 teaspoon sea salt

• 1/2 teaspoon garlic powder

• 3 tablespoons olive oil

Quiche Filling

• 2 tablespoons olive oil

• 1 large white or yellow onion, thinly sliced into half moons

• 8 ounces cremini mushrooms, sliced

• 1 (15-ounce) package extra firm tofu, drained

• 3 tablespoons garbanzo (chickpea) flour

• 1/4 cup nutritional yeast flakes

• 1/4 cup filtered water

• 1 tablespoon tahini

• 1 teaspoon apple cider vinegar

• 3/4 teaspoon sea salt + 1/2 teaspoon black salt (kala namak)*

• 1/2 teaspoon garlic powder

• 1/2 teaspoon ground turmeric (optional for color)

• Freshly ground black pepper

• 1/2 to 1 cup cherry tomatoes, thinly sliced into rounds

• Dried basil (optional garnish)

Instructions

• Preheat the oven to 350F. Lightly grease a rectangular tart tin (we recommend 14" x 4.5" if you have it—if you use a larger tart tin, there will still be plenty of crust and filling to fill it, it will just be a bit thinner).

• In a small mixing bowl, whisk together the ground flaxseed and 3 tablespoons of the water. Set aside for 5 minutes to thicken.

• In a large mixing bowl, whisk together the almond meal, oat flour, sea salt, and garlic powder. Add the flaxseed mixture, olive oil, and the remaining 1 1/2 tablespoons water. Stir to combine. The dough should be damp, in large crumbles, and should hold together when pressed between your fingers. 

• Transfer the dough to the prepared tart pan and use your fingers to press it evenly into the bottom of the pan and up the sides, creating an edge that is just as thick and robust as the bottom. Use a fork to poke several holes across the surface to promote venting while baking.

• Bake for 18 to 25 minutes (depending on your pan size), or until the crust is light golden and feels firm to the touch. Let cool slightly. Place the tart tin on top of a baking tray (makes it easier to transport to/from the oven once filled). Leave the oven on.

• While the crust bakes, prepare the filling.

• Heat the olive oil in a large sauté pan over medium-high heat.

• Add the onion and mushrooms. Sauté for 15 to 20 minutes, or until soft and caramelized, nudging them around the pan every few minutes or so. Season with a pinch of salt and black pepper and set aside.

• Crumble the tofu into a food processor. Add the garbanzo flour, nutritional yeast, water, tahini, vinegar, sea salt + black salt (if using), garlic powder, turmeric (if using), and a few grinds of black pepper. Process for 1 minute, or until completely smooth, stopping to scrape down the sides of the processor as needed. 

• Spoon the tofu mixture into the pan with the caramelized onions and mushrooms and stir to combine.

• Evenly spread the mixture into the tart shell, using a spatula to smooth the surface. Depending on the size of tart tin you're using, you may have extra filling. Simply spoon the excess into the slots of a greased muffin tin, filling about two-thirds of the way full, and bake alongside the tart for mini, crustless quiches.

• Decoratively top the surface of the tart with the cherry tomato rounds. Sprinkle with dried basil (if using). 

• Bake the tart (and crustless quiches—if you have any) for 30 to 40 minutes (will vary based on the size of your pan), or until the edges are golden brown and the middle of the quiche is firm to the touch. 

• Transfer the tart pan to an oven safe cooling rack and cool for at least 15 minutes before slicing.

• Slice and serve warm.

  Leftovers will keep for up to 4 days in the refrigerator when wrapped tightly. Reheat in a preheated 350F oven for 15 to 20 minutes, or until the filling is warmed through and the crust is crisp.

*Black salt adds an eggy flavor due to its sulfuric taste. I highly recommend using it, but if you don't have access to it, simply use another 1/2 teaspoon sea salt instead (so 1 1/4 teaspoon total salt—plus more to taste, if desired).

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