Mushroom Spinach Quiche {A Meatless Monday Recipe

This easy-to-make Mushroom Spinach Quiche is made of mushrooms, spinach, shallots, and Gruyère cheese. Great for breakfast, lunch, or dinner!

My first memory of quiche was from a recipe my mama used to make many moons ago when I was a teenager. The quiche had sausage, onions, and the usual cheese and egg custard mixture. It was delicious, and I got the recipe from her sometime later to make for David and myself.

I love to enjoy this vegetarian quiche recipe for Meatless Monday or any day of the week!

What is a Quiche?

A quiche is a savory egg custard baked in a pie crust shell with vegetables, cheeses, spices, and, often, meat. The base of a quiche filling is milk, cream, and eggs.

This easy-to-prepare mushroom spinach quiche is made with the perfect combination of mushrooms, spinach, and shallots, in a savory egg custard with Gruyère cheese.

Ingredients You’ll Need To Make This Quiche Recipe

The recipe card at the end of this post provides a detailed list of ingredients.

Pie Crust: I don’t always have the patience to make pie crust from scratch, so I usually purchase a store-bought 9-inch deep dish pie crust. Make sure you purchase or make a deep crust, so there’s room to hold all of the filling.

Oil: For sauteing the vegetables. I always use extra virgin olive oil but use whatever oil you prefer. Butter is ok too, but don’t let it burn.

Veggies: shallots, portobello mushrooms, garlic, and fresh spinach

Seasoning: Kosher salt, freshly cracked black pepper, and nutmeg enhance the flavor of the savory custard and spinach.

Custard Egg Mixture: whole milk, heavy cream, and eggs.

Cheese: grated Gruyère cheese adds savoriness without overshadowing the ingredients of the quiche. You can use swiss cheese if you cannot find Gruyère.

How To Make Mushroom Spinach Quiche

This quiche comes together in less than 30 minutes. Most of the prep time involves sauteing the veggies but is not very labor intensive.

Detailed instructions are provided in the recipe card at the end of this post.

Step #1: Prepare the Crust

It’s important to blind bake the pie crust before adding the filling to keep it from getting soggy. Essentially blind baking means partially baking the pie crust before adding the filling.

Blind bake the pie crust per package instructions. Remove from the oven and transfer to a wire rack to cool while making the filling.

Step #2: Saute The Veggies

Meanwhile, saute the shallots, and cook, stirring, until translucent but not brown, then add the mushrooms and season with salt and pepper. Cook for about 10 minutes, then add the spinach and cook until it wilts but is still bright green.

Step #3: Build the Quiche

Place the prepared pie crust pan on a baking sheet — this will catch any runoff there may be during baking.

Sprinkle half of the cheese evenly over the bottom of the crust. Then add the veggies and top with the remaining cheese.

Step #4 Prepare the Custard

Whisk together custard ingredients in a medium bowl. Season with nutmeg, salt, and pepper, to taste, and the mixture over the cheese and veggies into the pie crust.

Step #5 Bake the Quiche

Transfer the quiche to the 350-degree F oven and bake until just set in the center, 30 to 35 minutes.

How can I tell when the quiche is done?

Quiche will continue to cook after it’s removed from the oven. The center of the quiche should jiggle slightly when gently shaken. Overbaked quiche may curdle. 

Knife Test: you can test for doneness by inserting a knife midway between the center and the edge of the piecrust. If the knife is clean, the quiche is done. If the knife comes out with filling on it, bake a few more minutes and test again.

Step #6 Cool & Serve

Cool on a wire rack for about 10 minutes before slicing.

Storage, Freezing, and Reheating Quiche

• Storage: Wrap leftover quiche in shrink wrap or aluminum foil and refrigerate for 3-4 days.
• Freezing: Ensure the baked quiche is entirely cool. I recommend storing it overnight in the fridge before freezing it. Wrap in plastic wrap and then cover with foil to ensure an airtight seal. Freeze for 2-3 months.
• Reheating: Bake the quiche covered in aluminum foil (remove any plastic wrap) in a 350-degree F oven for 30 to 45 minutes from frozen or 5-20 minutes from refrigerated. Or until the inside of the quiche is at 165 degrees Fahrenheit.

Tips for Making Quiche

• Choose a deep-dish pie crust and bake before filling it to avoid a soggy crust. The cheese on the bottom of the crust will help form a barrier also.
• Make individual quiches in smaller pastry tart shells, muffin tins, or hollowed-out vegetables, such as bell peppers.
• Make fillings from your favorite foods or leftovers. You can use any combination of vegetables and cheese. If it isn’t Meatless Monday, you can add meat.
• Ingredients for the filling should be cooked, not raw, and all ingredients should be well drained.
• For a richer quiche, cream and whole milk or substitute with half-and-half. The quiche isn’t as good with low-fat or skim milk.

This mushroom and spinach quiche is an excellent meal for breakfast, lunch, or dinner. It’ll be delicious for whichever meal you choose, for sure!

Are you making mushroom spinach quiche? We’d love your feedback. Leave us a comment and a star rating below. We value your opinion and appreciate your time.

See ya on the mountain!

More Vegetarian Breakfast and Brunch Recipes You’ll Love

• VEGETABLE STRATA
• EGG-STUFFED POBLANO PEPPER BOATS
• CRUSTLESS ASPARAGUS RICOTTA QUICHE
• VEGETABLE QUICHE
• MUSHROOM CAPS WITH BAKED EGGS