Mouthwatering Spinach and Mushroom Quiche

I used to think quiche was one of those fancy brunch dishes you could only get at a nice restaurant. The kind of thing that seemed too complicated to make at home on a regular Tuesday night. Then I realized it’s basically just eggs, cheese, and whatever vegetables you have hanging out in your fridge, all baked in a pie crust.

This spinach and mushroom version is my go-to now because it looks like you spent hours in the kitchen, but really it comes together in about 20 minutes of actual work. The rest is just oven time, which means you can be doing literally anything else—folding laundry, helping with homework, scrolling through your phone. And here’s the best part: it tastes just as good for dinner as it does reheated for breakfast the next day.

What Kind of Mushrooms Should I Use?

You’ve got plenty of options when it comes to mushrooms for this quiche. The recipe calls for mixed wild mushrooms like cremini, shiitake, button, or oyster, but honestly, you can use whatever looks good at your grocery store or farmers market. Cremini and button mushrooms are the most budget-friendly and have a mild, earthy flavor that works great here. If you want something with a bit more depth, shiitake mushrooms add a meaty texture and richer taste, while oyster mushrooms bring a slightly sweet, delicate flavor. You can stick with just one variety if that’s easier, or mix and match a few different types for more complexity in your quiche.

Options for Substitutions

This quiche recipe is pretty forgiving when it comes to swaps, so here are some options if you need to make changes:

• Mixed wild mushrooms: Any mushroom variety works here – even plain white button mushrooms will taste great. You can also use a single type of mushroom if that’s what you have on hand.
• Fresh baby spinach: Frozen spinach works too! Use about 10 ounces of frozen spinach, thaw it completely, and squeeze out as much water as possible before adding it to the quiche. You can also swap in other greens like kale or Swiss chard – just make sure to remove any tough stems and chop them finely.
• Gruyère cheese: While Gruyère gives this quiche a nice nutty flavor, you can substitute with Swiss cheese, white cheddar, or even a mix of mozzarella and parmesan. Just stick with good melting cheeses.
• Half-and-half: If you don’t have half-and-half, you can use all whole milk (so ½ cup total) or heavy cream for a richer quiche.
• Fresh thyme: Dried thyme works in a pinch – just use 1 teaspoon instead of the tablespoon of fresh. You could also try other herbs like oregano or Italian seasoning.
• Sweet onion: Regular yellow or white onions are perfectly fine substitutes. Shallots also work well if you want a milder onion flavor.

Watch Out for These Mistakes While Baking

The biggest mistake when making quiche is not cooking your mushrooms long enough, which releases excess moisture that can make your quiche watery – make sure to cook them until they’re golden and most of their liquid has evaporated before adding the onions.

Another common error is skipping the 10-minute resting period after baking, as cutting into the quiche too soon will cause the custard to run all over your plate instead of holding its shape.

To avoid a soggy bottom, you can blind-bake your pie crust for 10 minutes before adding the filling, or simply make sure your vegetables are completely cooled before mixing them with the egg mixture.

Finally, don’t overbake your quiche – it’s done when the center still has a slight jiggle but the edges are set, since the residual heat will finish cooking it during the resting time.

What to Serve With Spinach and Mushroom Quiche?

Quiche is one of those dishes that works for breakfast, lunch, or dinner, so you’ve got lots of options for what to serve alongside it. A simple arugula or mixed greens salad with a light vinaigrette is my go-to because the peppery greens balance out the richness of the eggs and cheese. If you’re serving it for brunch, fresh fruit like berries or melon slices are always a hit, or you could do roasted potatoes with herbs for something more filling. For a fancier spread, add some crusty baguette slices and a small charcuterie board with prosciutto, olives, and pickled vegetables.

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 store individual slices 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 the whole quiche or individual slices for up to 3 months. Wrap it well in plastic wrap and then in foil to prevent freezer burn. I like to freeze individual portions so I can just grab one when I need a quick meal.

Reheat: Warm up slices in the microwave for about 1-2 minutes, or reheat in a 350°F oven for 15-20 minutes until heated through. If reheating from frozen, let it thaw in the fridge overnight first for best results, though you can also reheat straight from frozen by adding a few extra minutes.

Estimated Nutrition

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

• Calories: 1100-1300
• Protein: 55-65 g
• Fat: 80-95 g
• Carbohydrates: 30-40 g

Ingredients

For the filling:

• 8 oz mixed mushrooms (cremini, button, or shiitake work well)
• 1.5 cups shredded Gruyère cheese (I use the aged variety for best flavor)
• 1 tbsp garlic (freshly minced)
• 5 oz fresh baby spinach (wilts down significantly when cooked)
• 1.5 cups sweet onion (diced into 1/4-inch pieces)
• 2 tbsp extra-virgin olive oil (or any neutral oil like canola)

For the custard:

• 6 large eggs (room temperature)
• 1/4 tsp ground pepper (freshly ground preferred for more flavor)
• 1/4 cup whole milk
• 1/4 tsp salt
• 1/4 cup half-and-half (makes it extra creamy and rich)
• 1 tbsp fresh thyme leaves (freshly stripped from stems)
• 1 tbsp Dijon mustard

Step 1: Prepare Mise en Place and Preheat

• 8 oz mixed mushrooms, sliced
• 1.5 cups sweet onion, diced
• 1 tbsp garlic, minced
• 1 tbsp fresh thyme leaves
• 1.5 cups shredded Gruyère cheese

Preheat your oven to 375°F.

While it heats, prepare all your ingredients: slice the mushrooms into 1/4-inch pieces, dice the sweet onion into 1/4-inch pieces, mince the garlic, strip the thyme leaves from their stems, and shred the Gruyère cheese if not already done.

This prep work ensures you won’t be rushed once cooking begins and allows you to focus on building flavors.

Step 2: Sauté Vegetables and Build Flavor

• 2 tbsp extra-virgin olive oil
• 8 oz mixed mushrooms, sliced
• 1.5 cups sweet onion, diced
• 1 tbsp garlic, minced
• 5 oz fresh baby spinach

Heat the olive oil in a large skillet over medium-high heat.

Add the sliced mushrooms and cook for 8 minutes, stirring occasionally, until they release their moisture and begin to brown—this develops deep umami flavors.

Add the diced onion and minced garlic, cooking for another 5 minutes until the onion is soft and translucent.

Finally, add the fresh spinach and cook for 1-2 minutes just until wilted.

I like to use fresh garlic here because it infuses the vegetables with much more flavor than pre-minced garlic from a jar.

Remove the skillet from heat and set aside to cool slightly.

Step 3: Prepare the Custard Base

• 6 large eggs
• 1/4 cup whole milk
• 1/4 cup half-and-half
• 1 tbsp Dijon mustard
• 1 tbsp fresh thyme leaves
• 1/4 tsp salt
• 1/4 tsp ground pepper

In a medium bowl, whisk together the room-temperature eggs, milk, half-and-half, Dijon mustard, fresh thyme leaves, salt, and pepper until well combined and smooth.

The mustard adds a subtle depth and helps bind the filling together.

Room-temperature eggs integrate more smoothly into the custard, creating a more uniform texture throughout the quiche.

Step 4: Assemble the Filling

• custard mixture from Step 3
• sautéed vegetable mixture from Step 2
• 1.5 cups shredded Gruyère cheese

Pour the custard mixture from Step 3 into the skillet with the cooled sautéed vegetables from Step 2.

Gently fold in the shredded Gruyère cheese, stirring just until combined.

Be careful not to overmix—gentle folding keeps the filling tender and prevents the cheese from becoming stringy.

This combined filling is now ready to transfer to the quiche pan.

Step 5: Prepare Pan and Add Filling

• 2 tbsp extra-virgin olive oil
• combined filling from Step 4

Lightly oil a 9-inch pie pan or quiche dish with a thin coating of oil, making sure to coat the bottom and sides evenly to prevent sticking.

Pour the combined filling from Step 4 into the prepared pan, spreading it evenly.

The filling should sit just below the rim to allow for slight puffing during baking.

Step 6: Bake Until Set and Golden

Place the quiche in the preheated 375°F oven and bake for 30 minutes, until the filling is set but still slightly jiggly in the very center (about a 2-inch circle in the middle), and the top is lightly golden.

The residual heat will continue cooking the center as it cools.

If the top begins to brown too quickly, tent loosely with foil for the final 10 minutes of baking.

Step 7: Rest and Serve

Remove the quiche from the oven and let it rest at room temperature for 10 minutes before slicing.

This resting period allows the custard to set fully and makes slicing much cleaner and easier.

Serve warm or at room temperature—the quiche is delicious either way!

Mouthwatering Spinach and Mushroom Quiche

Delicious Mouthwatering Spinach and Mushroom Quiche recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 30 minutes mins

Total Time 47 minutes mins

Servings 6 slices

Calories 1200 kcal

Ingredients

  

For the filling:

• 8 oz mixed mushrooms (cremini, button, or shiitake work well)
• 1.5 cups shredded Gruyère cheese (I use the aged variety for best flavor)
• 1 tbsp garlic (freshly minced)
• 5 oz fresh baby spinach (wilts down significantly when cooked)
• 1.5 cups sweet onion (diced into 1/4-inch pieces)
• 2 tbsp extra-virgin olive oil (or any neutral oil like canola)

For the custard:

• 6 large eggs (room temperature)
• 1/4 tsp ground pepper (freshly ground preferred for more flavor)
• 1/4 cup whole milk
• 1/4 tsp salt
• 1/4 cup half-and-half (makes it extra creamy and rich)
• 1 tbsp fresh thyme leaves (freshly stripped from stems)
• 1 tbsp Dijon mustard

Instructions

 

• Preheat your oven to 375°F. While it heats, prepare all your ingredients: slice the mushrooms into 1/4-inch pieces, dice the sweet onion into 1/4-inch pieces, mince the garlic, strip the thyme leaves from their stems, and shred the Gruyère cheese if not already done. This prep work ensures you won't be rushed once cooking begins and allows you to focus on building flavors.
• Heat the olive oil in a large skillet over medium-high heat. Add the sliced mushrooms and cook for 8 minutes, stirring occasionally, until they release their moisture and begin to brown—this develops deep umami flavors. Add the diced onion and minced garlic, cooking for another 5 minutes until the onion is soft and translucent. Finally, add the fresh spinach and cook for 1-2 minutes just until wilted. I like to use fresh garlic here because it infuses the vegetables with much more flavor than pre-minced garlic from a jar. Remove the skillet from heat and set aside to cool slightly.
• In a medium bowl, whisk together the room-temperature eggs, milk, half-and-half, Dijon mustard, fresh thyme leaves, salt, and pepper until well combined and smooth. The mustard adds a subtle depth and helps bind the filling together. Room-temperature eggs integrate more smoothly into the custard, creating a more uniform texture throughout the quiche.
• Pour the custard mixture from Step 3 into the skillet with the cooled sautéed vegetables from Step 2. Gently fold in the shredded Gruyère cheese, stirring just until combined. Be careful not to overmix—gentle folding keeps the filling tender and prevents the cheese from becoming stringy. This combined filling is now ready to transfer to the quiche pan.
• Lightly oil a 9-inch pie pan or quiche dish with a thin coating of oil, making sure to coat the bottom and sides evenly to prevent sticking. Pour the combined filling from Step 4 into the prepared pan, spreading it evenly. The filling should sit just below the rim to allow for slight puffing during baking.
• Place the quiche in the preheated 375°F oven and bake for 30 minutes, until the filling is set but still slightly jiggly in the very center (about a 2-inch circle in the middle), and the top is lightly golden. The residual heat will continue cooking the center as it cools. If the top begins to brown too quickly, tent loosely with foil for the final 10 minutes of baking.
• Remove the quiche from the oven and let it rest at room temperature for 10 minutes before slicing. This resting period allows the custard to set fully and makes slicing much cleaner and easier. Serve warm or at room temperature—the quiche is delicious either way!