Spinach & Feta Quiche with Sweet Potato Crust

This spinach and feta quiche with sweet potato crust has revolutionized my brunch game and become my secret weapon for impressing guests while keeping things surprisingly healthy. The sweet potato slices create a naturally gluten free crust that adds subtle sweetness and gorgeous color, while the creamy egg filling packed with wilted spinach and tangy feta delivers all the comfort you crave. I stumbled upon this combination when I ran out of pie crusts one Sunday morning and had sweet potatoes sitting on my counter.

I originally created this recipe for a friend with celiac disease who was missing quiche terribly. After one bite, she declared it better than any traditional version she remembered. Now I make it regularly because my whole family loves how the sweet potato crust adds this wonderful earthy sweetness that pairs so beautifully with the salty feta and fresh spinach.

Ingredients

• Cooking spray: creates the perfect non stick surface for easy removal
• 2 medium sweet potatoes: peeled and sliced into 1/8 inch rounds form the foundation crust that bakes up tender yet sturdy
• 1 teaspoon neutral oil: like canola or avocado prevents sticking and helps vegetables cook evenly
• ½ cup sliced onion: adds aromatic depth and slight sweetness that complements the other flavors
• 1 five ounce bag fresh baby spinach: wilts down perfectly and provides iron plus vibrant color
• ½ cup 1% low fat milk: creates the creamy custard base without excess calories
• ¼ teaspoon kosher salt: enhances all the natural flavors
• ¼ teaspoon black pepper: adds gentle heat and complexity
• ¼ teaspoon crushed red pepper flakes: brings subtle warmth without overwhelming
• 4 large eggs: provide the protein structure that sets the quiche
• 2 large egg whites: add extra protein while keeping the texture light
• 1½ ounces crumbled feta cheese: about 1/3 cup delivers tangy Mediterranean flavor

Step by Step Instructions

Preheat and Prepare:

Set your oven to 350°F and position the rack in the center for even baking. Lightly coat your 9 inch pie dish with cooking spray, making sure to get the bottom and sides completely covered. This step is crucial for easy removal later and prevents any sticking issues with the sweet potato crust.

Create the Sweet Potato Crust:

Arrange those beautiful sweet potato rounds in overlapping circles starting from the center and working your way out to cover the bottom completely. Then carefully press additional slices around the sides of the dish, overlapping them slightly to create a seamless crust. Spray the arranged potatoes lightly with cooking spray to help them brown and crisp. Bake for exactly 20 minutes until they become slightly tender but still hold their shape.

Boost the Temperature:

Remove the partially baked crust from the oven and immediately increase the temperature to 375°F. This higher temperature will help set the custard filling properly and create that perfect golden top we're after.

Sauté the Vegetables:

Heat that teaspoon of oil in a nonstick skillet over medium heat until it shimmers slightly. Add the sliced onions and sauté for 3 minutes, stirring occasionally, until they start to soften and become fragrant. Add all that fresh spinach and continue cooking for another 3 minutes, stirring frequently, until the spinach wilts completely and releases its moisture. Remove from heat and let the mixture cool slightly to prevent scrambling the eggs when you combine everything.

Prepare the Custard Base:

In a medium bowl, whisk together the milk, kosher salt, black pepper, and red pepper flakes until well combined. Add the whole eggs and egg whites, whisking vigorously until the mixture is completely smooth and homogeneous. This creates the silky custard that will set around your vegetables.

Assemble Your Masterpiece:

Spread that beautifully sautéed spinach and onion mixture evenly over your prebaked sweet potato crust, making sure it reaches all the edges. Pour the prepared egg mixture slowly over the vegetables, allowing it to settle into all the nooks and crannies. Sprinkle the crumbled feta cheese evenly over the surface for those delicious pockets of tangy flavor in every bite.

Final Bake:

Slide the assembled quiche into your 375°F oven and bake for 35 minutes, or until the center feels set when you gently jiggle the pan. The top should be lightly golden and the filling should no longer look wet in the center. Let it rest for 5 minutes before slicing to allow the custard to firm up completely.

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Storage and Reheating

Store leftover quiche covered in the refrigerator for up to 4 days. For the best texture when reheating, use a 300°F oven for 15 to 20 minutes rather than the microwave. You can also reheat individual slices in a toaster oven for 8 to 10 minutes. The sweet potato crust maintains its texture beautifully, unlike traditional pastry that can become soggy. For longer storage, wrap individual slices tightly in plastic wrap then aluminum foil and freeze for up to 3 months.

Ingredient Substitutions

Regular yellow onions work perfectly if you prefer a stronger onion flavor, or try shallots for something more delicate. Frozen spinach can substitute for fresh in a pinch, but make sure to thaw it completely and squeeze out all excess moisture to prevent a watery filling. Goat cheese makes an excellent substitute for feta and provides similar tangy flavor with creamier texture. For dairy free versions, use unsweetened almond milk and omit the cheese, or try a plant based feta alternative.

Serving Suggestions

This quiche shines at brunch alongside fresh fruit salad and crispy bacon or breakfast sausage. For dinner, serve with a simple arugula salad dressed with lemon vinaigrette to cut through the richness. The Mediterranean flavors pair beautifully with roasted cherry tomatoes and a glass of crisp white wine. Cut into smaller wedges, it makes elegant appetizers for parties or book club gatherings.

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The Sweet Potato Revolution

Sweet potatoes make surprisingly excellent quiche crusts because they hold their shape when baked and provide natural sweetness that complements savory fillings. The key is slicing them consistently thin so they cook evenly and form a cohesive base. This technique works with other root vegetables too, like thinly sliced regular potatoes or even butternut squash for different flavor profiles.

Recipe FAQs

→ Can I make this quiche ahead of time?

Yes, you can bake the quiche ahead and reheat individual slices in the oven or microwave when ready to serve.

→ What can I use instead of sweet potato for the crust?

You can use thinly sliced Yukon Gold potatoes or a traditional pie crust as a substitute.

→ Is this quiche suitable for vegetarians?

Yes, it contains no meat and uses vegetarian-friendly ingredients like eggs, cheese, and vegetables.

→ How do I know when the quiche is fully cooked?

The quiche is done when the center is set and doesn't jiggle when lightly shaken. A knife inserted should come out clean.

→ Can I freeze the quiche?

Yes, let it cool completely, slice it, and wrap the pieces individually before freezing for up to 3 months.