Mouthwatering Spinach and Mushroom Quiche

Why I Love This Recipe

I love how this quiche balances rich and light so effortlessly. The sautéed mushrooms bring deep umami, the onions and garlic add a touch of sweetness, and the fresh thyme gives the whole dish a subtle herbal note. Gruyère cheese melts beautifully, creating a creamy texture that works perfectly with the egg custard. It’s incredibly satisfying, and it reheats beautifully, so I often make it ahead for a stress-free meal.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

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

Directions

1. I preheat the oven to 375°F and prepare all my ingredients—slicing mushrooms, dicing onions, mincing garlic, and shredding the Gruyère. This makes everything go smoothly once I start cooking.

2. I heat the olive oil in a large skillet over medium-high heat and add the sliced mushrooms. I cook them for about 8 minutes until they release their moisture and begin to brown. Then I stir in the diced onion and garlic, cooking for another 5 minutes until softened. I add the spinach last and cook just until wilted, about 1–2 minutes. I take the pan off the heat and let the mixture cool slightly.

3. In a medium bowl, I whisk together the eggs, milk, half-and-half, Dijon mustard, thyme, salt, and pepper until smooth. The mustard adds a little kick and helps bind everything together.

4. I pour the custard into the skillet with the cooled vegetables and gently fold in the shredded Gruyère. I stir just until combined, being careful not to overmix.

5. I lightly oil a 9-inch pie or quiche pan and pour in the filling, spreading it out evenly. It should sit just below the rim of the dish.

6. I bake the quiche for 30 minutes, or until the filling is set with a slight jiggle in the center and the top is lightly golden. If it browns too quickly, I tent it loosely with foil in the last 10 minutes.

7. Once it’s done, I let it rest for 10 minutes before slicing. This helps everything set up perfectly and makes for cleaner slices.

Servings and timing

This quiche serves 6 generous slices and takes a total of 47 minutes from start to finish: 15 minutes of prep and 30 minutes in the oven. It’s ideal for weekend brunches or when I want something make-ahead and satisfying.

Variations

Sometimes I switch up the veggies with roasted red peppers, leeks, or even kale. For a meatier version, I add some cooked bacon or sausage. If I don’t have Gruyère, I use sharp white cheddar or Swiss cheese—both melt beautifully and offer great flavor. I’ve also made mini versions in muffin tins for portable, single-serve bites.

Storage/Reheating

I store leftover quiche in the fridge, covered, for up to 4 days. When reheating, I pop a slice in the oven at 325°F for about 10 minutes, or until warmed through. If I’m in a rush, I use the microwave, but the crust won’t stay crisp. This quiche also freezes well—I just wrap individual slices in foil and reheat them straight from frozen.

FAQs

Can I make this quiche crustless?

Yes, I often skip the crust for a lighter version. I just be sure to grease the pan well, and it turns out beautifully every time.

Can I use frozen spinach instead of fresh?

I can, but I always make sure to thaw and squeeze out as much water as possible before adding it, so the filling doesn’t get soggy.

Is it okay to make this ahead of time?

Absolutely. I’ve made it the night before and simply reheated it the next day. It’s even better after the flavors have had time to settle.

What’s the best cheese substitute for Gruyère?

I like using Swiss or sharp white cheddar if I don’t have Gruyère on hand. Both melt well and bring great flavor to the dish.

Can I freeze the entire quiche?

Yes, once it cools completely, I wrap it tightly and freeze it whole. To reheat, I bake it at 350°F from frozen for about 30–40 minutes.

Conclusion

This Spinach and Mushroom Quiche is one of those recipes I come back to again and again. It’s hearty, flavorful, and endlessly customizable. Whether I’m hosting brunch, packing lunch, or just treating myself to something delicious, this quiche never disappoints.

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