Simple Gluten Free Spinach and Mushroom Quiche

Finding a satisfying breakfast or brunch option that works for gluten-free diets can feel impossible sometimes. Most quiche recipes rely on a buttery crust that’s off-limits, and let’s be honest, crustless versions often get dismissed as boring or diet food that nobody actually wants to eat.

But here’s the thing: this gluten-free spinach and mushroom quiche proves that skipping the crust doesn’t mean skipping flavor. It’s packed with fresh vegetables, two types of cheese, and comes together in one dish with minimal fuss. Plus, it reheats beautifully for easy breakfasts throughout the week.

What Kind of Mushrooms Should I Use?

For this quiche, you can use pretty much any mushroom variety you find at the grocery store and it’ll turn out great. White button mushrooms are the most common and affordable option, and they have a mild flavor that works well with the spinach and cheese. If you want something with a bit more earthy flavor, baby bella (cremini) mushrooms are a solid choice and usually just a dollar or two more. Just make sure to clean your mushrooms with a damp paper towel rather than rinsing them under water, since mushrooms absorb moisture like a sponge and can make your quiche watery. After chopping them up, you might want to sauté them for a few minutes to cook off some of that extra moisture before adding them to your egg mixture.

Options for Substitutions

This quiche is pretty forgiving when it comes to swapping ingredients around:

• Egg whites: If you don’t want to separate eggs, just use 6 whole eggs instead of 4 eggs plus 4 whites. The quiche will be a bit richer, but it’ll taste great.
• 2% milk: Any milk works here – whole milk makes it creamier, while skim keeps it lighter. You can also use half-and-half for an extra rich quiche, or unsweetened almond milk if you’re avoiding dairy (though the texture will be slightly different).
• Cheddar and parmesan cheese: Mix and match your favorite cheeses! Gruyere, Swiss, mozzarella, or goat cheese all work well. Just keep the total amount around 1 cup.
• Fresh spinach: Frozen spinach works great too – just thaw it completely and squeeze out all the excess water before adding it to the quiche. You’ll need about 1 cup of thawed, drained spinach.
• Mushrooms: Any mushroom variety will do the trick – button, cremini, shiitake, or portobello. You can also swap them out for other veggies like bell peppers, zucchini, or broccoli.
• White onion: Yellow onions, shallots, or even green onions can stand in for white onion without any issues.

Watch Out for These Mistakes While Baking

The biggest mistake when making crustless quiche is not cooking down your vegetables enough beforehand, which releases excess moisture that can make your quiche watery and prevent it from setting properly – make sure to cook the mushrooms until they’ve released their liquid and the spinach is completely wilted with no water pooling in the pan.

Another common error is pouring the egg mixture into a cold pie pan, so lightly grease your pan and let those cooked vegetables cool for a few minutes before adding the eggs to avoid curdling.

Don’t skip the 15-minute resting time after baking, as this allows the eggs to finish setting and makes slicing much cleaner, and if you notice the edges browning too quickly, tent the quiche with foil halfway through baking to keep it from drying out.

What to Serve With Spinach and Mushroom Quiche?

This quiche makes a great brunch or light dinner, and I love serving it with a simple mixed greens salad tossed with a lemon vinaigrette to balance out the richness of the eggs and cheese. Fresh fruit like sliced strawberries, melon, or grapes on the side adds a nice sweet contrast and makes the meal feel more complete. If you’re serving this for breakfast or brunch, some crispy bacon or breakfast sausage links are always a hit, and don’t forget to put out some toast or fresh croissants for anyone who wants a little extra carbs on their plate. A mimosa or fresh orange juice rounds out the whole brunch vibe perfectly.

Storage Instructions

Store: This quiche keeps really well in the fridge for up to 4 days. Just cover it tightly with plastic wrap or aluminum foil, or slice it into portions and store in an airtight container. It’s great for meal prep since you can grab a slice for breakfast or lunch throughout the week.

Freeze: You can freeze this quiche whole or in individual slices for up to 2 months. Wrap it well in plastic wrap and then in foil to prevent freezer burn. I like to freeze individual slices so I can pull out just what I need for a quick breakfast.

Reheat: Warm up refrigerated slices in the microwave for about 45-60 seconds, or pop them in a 350°F oven for 10-15 minutes until heated through. If reheating from frozen, let it thaw in the fridge overnight first, or add a few extra minutes to the reheating time.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 520-600
• Protein: 55-65 g
• Fat: 25-30 g
• Carbohydrates: 22-27 g

Ingredients

• 1/2 cup shredded Parmesan cheese (freshly grated preferred)
• 1/4 tsp salt
• 4 large eggs
• 1 tsp garlic (minced or powder)
• 6 oz fresh spinach leaves (lightly packed, roughly chopped)
• 8 oz mushrooms (sliced thin for even cooking)
• 1/4 large white onion (finely diced, about 1/4-inch pieces)
• 4 egg whites (room temperature for better binding)
• 1 cup 2% milk
• 1/2 cup shredded cheddar cheese (I use Cabot for better melting)

Step 1: Prepare the Mise en Place and Preheat

• 1 tsp garlic
• 1/4 large white onion
• 8 oz mushrooms
• 6 oz fresh spinach leaves
• 1/2 cup shredded Parmesan cheese

Preheat your oven to 350°F.

While it heats, prepare all ingredients: mince the garlic, finely dice the onion into 1/4-inch pieces, thinly slice the mushrooms for even cooking, roughly chop the fresh spinach, and grate the Parmesan cheese fresh if possible—this makes a noticeable difference in flavor and melting quality.

Having everything prepped and ready will make the cooking process smooth and stress-free.

Step 2: Sauté the Vegetables Until Tender

• 1 tsp garlic
• 1/4 large white onion
• 8 oz mushrooms
• 6 oz fresh spinach leaves

In a large skillet over medium-high heat, sauté the diced onion and minced garlic until fragrant, about 1 minute.

Add the sliced mushrooms and cook for 5-7 minutes, stirring occasionally, until they release their moisture and begin to brown slightly.

The mushrooms will shrink significantly as they cook, which is exactly what you want—this concentrates their earthy flavor.

Once the mushrooms are tender and any excess liquid has mostly evaporated, add the chopped spinach and stir constantly for 2-3 minutes until it wilts completely and any remaining liquid cooks off.

Step 3: Prepare the Egg Custard Base

• 4 large eggs
• 4 egg whites
• 1 cup 2% milk
• 1/4 tsp salt
• 1 tsp garlic

In a large mixing bowl, combine the 4 large eggs, 4 egg whites (room temperature eggs bind better than cold ones), 1 cup milk, salt, and minced garlic.

Whisk vigorously for about 20 seconds until the mixture is well combined and slightly frothy—this incorporates air and ensures an evenly cooked, creamy quiche.

Don’t overmix beyond this point, as excessive beating can make the texture tough.

Step 4: Assemble the Quiche in the Pie Pan

• sautéed vegetable mixture from Step 2
• 1/2 cup shredded cheddar cheese
• 1/4 cup shredded Parmesan cheese
• egg custard mixture from Step 3

Spread the sautéed vegetable mixture (from Step 2) evenly across the bottom of a 9-inch pie pan or similar-sized baking dish.

I recommend spreading it in a single, even layer to ensure every bite has the same proportion of vegetables.

Sprinkle the shredded cheddar cheese and 1/4 cup of the Parmesan cheese over the vegetables.

Pour the egg custard mixture (from Step 3) slowly over the top, allowing it to settle and distribute evenly around the vegetables.

The egg should come up to about three-quarters full in the pan.

Step 5: Bake Until Set and Golden

Place the assembled quiche in the preheated 350°F oven and bake for 35 minutes, until the edges are set but the center still has a slight jiggle when you gently shake the pan—this means the center will be creamy rather than rubbery.

The top should be lightly golden brown.

If the top begins to brown too quickly before the center is set, loosely tent it with aluminum foil for the remaining baking time.

Step 6: Finish and Rest

• 1/4 cup shredded Parmesan cheese

Remove the quiche from the oven and immediately sprinkle the remaining 1/4 cup of Parmesan cheese over the top while it’s still hot, so it melts slightly and adheres to the surface.

Allow the quiche to rest at room temperature for 15 minutes before slicing and serving—this resting period allows the egg to fully set and makes it much easier to cut clean slices without the custard running.

Simple Gluten Free Spinach and Mushroom Quiche

Delicious Simple Gluten Free Spinach and Mushroom Quiche recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 35 minutes mins

Total Time 50 minutes mins

Servings 6 servings

Calories 560 kcal

Ingredients

  

• 1/2 cup shredded Parmesan cheese (freshly grated preferred)
• 1/4 tsp salt
• 4 large eggs
• 1 tsp garlic (minced or powder)
• 6 oz fresh spinach leaves (lightly packed, roughly chopped)
• 8 oz mushrooms (sliced thin for even cooking)
• 1/4 large white onion (finely diced, about 1/4-inch pieces)
• 4 egg whites (room temperature for better binding)
• 1 cup 2% milk
• 1/2 cup shredded cheddar cheese (I use Cabot for better melting)

Instructions

 

• Preheat your oven to 350°F. While it heats, prepare all ingredients: mince the garlic, finely dice the onion into 1/4-inch pieces, thinly slice the mushrooms for even cooking, roughly chop the fresh spinach, and grate the Parmesan cheese fresh if possible—this makes a noticeable difference in flavor and melting quality. Having everything prepped and ready will make the cooking process smooth and stress-free.
• In a large skillet over medium-high heat, sauté the diced onion and minced garlic until fragrant, about 1 minute. Add the sliced mushrooms and cook for 5-7 minutes, stirring occasionally, until they release their moisture and begin to brown slightly. The mushrooms will shrink significantly as they cook, which is exactly what you want—this concentrates their earthy flavor. Once the mushrooms are tender and any excess liquid has mostly evaporated, add the chopped spinach and stir constantly for 2-3 minutes until it wilts completely and any remaining liquid cooks off.
• In a large mixing bowl, combine the 4 large eggs, 4 egg whites (room temperature eggs bind better than cold ones), 1 cup milk, salt, and minced garlic. Whisk vigorously for about 20 seconds until the mixture is well combined and slightly frothy—this incorporates air and ensures an evenly cooked, creamy quiche. Don't overmix beyond this point, as excessive beating can make the texture tough.
• Spread the sautéed vegetable mixture (from Step 2) evenly across the bottom of a 9-inch pie pan or similar-sized baking dish. I recommend spreading it in a single, even layer to ensure every bite has the same proportion of vegetables. Sprinkle the shredded cheddar cheese and 1/4 cup of the Parmesan cheese over the vegetables. Pour the egg custard mixture (from Step 3) slowly over the top, allowing it to settle and distribute evenly around the vegetables. The egg should come up to about three-quarters full in the pan.
• Place the assembled quiche in the preheated 350°F oven and bake for 35 minutes, until the edges are set but the center still has a slight jiggle when you gently shake the pan—this means the center will be creamy rather than rubbery. The top should be lightly golden brown. If the top begins to brown too quickly before the center is set, loosely tent it with aluminum foil for the remaining baking time.
• Remove the quiche from the oven and immediately sprinkle the remaining 1/4 cup of Parmesan cheese over the top while it's still hot, so it melts slightly and adheres to the surface. Allow the quiche to rest at room temperature for 15 minutes before slicing and serving—this resting period allows the egg to fully set and makes it much easier to cut clean slices without the custard running.