Delicious Caramelized Onion and Mushroom Quiche Recipe

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If you’re looking to whip up a delicious brunch dish that will impress your friends and family, look no further than this mouth-watering Caramelized Onion and Mushroom Quiche recipe. Packed with rich flavors and a creamy, custardy filling, this quiche is a showstopper. Imagine biting into a flaky crust filled with sweetly caramelized onions, earthy mushrooms, and a cheesy custard that melds everything together in perfect harmony. It’s the perfect balance of savory and indulgence, making it an ideal choice for any brunch gathering. Get ready to wow your taste buds and leave everyone asking for seconds!

Delicious Caramelized Onion and Mushroom Quiche Recipe


For the crust:

  • 1 1/2 cups all-purpose flour
  • 1/2 teaspoon salt
  • 1/2 cup unsalted butter, chilled and diced into small cubes
  • 4-5 tablespoons ice water

For the filling:

  • 2 tablespoons olive oil
  • 2 large onions, thinly sliced
  • 8 ounces mushrooms, sliced
  • 4 large eggs
  • 1 cup heavy cream
  • 1 teaspoon dried thyme
  • 1/2 teaspoon salt
  • 1/4 teaspoon black pepper
  • 1 cup shredded Gruyere cheese

For the caramelized onions:

  • 2 tablespoons olive oil
  • 2 large onions, thinly sliced
  • 1 teaspoon sugar
  • 1/2 teaspoon salt



  1. Preheat your oven to 375°F (190°C).
  2. Grease a 9-inch (23 cm) tart pan or pie dish.

Making the crust:

  1. In a large mixing bowl, combine the flour and salt.
  2. Add the diced butter and use a pastry cutter or your fingertips to rub the butter into the flour, until it resembles coarse crumbs.
  3. Gradually add the ice water, one tablespoon at a time, mixing until the dough comes together.
  4. Shape the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 30 minutes.
  5. Once chilled, roll out the dough on a lightly floured surface to fit your tart pan or pie dish.
  6. Press the rolled-out dough into the pan, making sure to press it evenly into the sides.
  7. Trim any excess dough from the edges.

Making the filling:

  1. Heat the olive oil in a large skillet over medium-low heat.
  2. Add the sliced onions and cook, stirring occasionally, until they become caramelized and golden brown, about 20-25 minutes.
  3. Remove the caramelized onions from the skillet and set aside.
  4. In the same skillet, add the sliced mushrooms and cook until they release their moisture and become golden brown, about 10 minutes.
  5. In a mixing bowl, whisk together the eggs, heavy cream, dried thyme, salt, and black pepper.
  6. Stir in the shredded Gruyere cheese, caramelized onions, and cooked mushrooms until well combined.

Assembling the quiche:

  1. Spread the filling mixture evenly over the prepared crust.
  2. Smooth the top with a spatula.

Baking the quiche:

  1. Place the quiche in the preheated oven and bake for 35-40 minutes, or until the filling is set and the crust is golden brown.
  2. Remove from the oven and let it cool for a few minutes before slicing and serving.


Cooking Tips:

  • For even caramelization of the onions, make sure to cook them over low heat and stir occasionally.
  • You can add some chopped fresh herbs, like thyme or rosemary, to the filling for an extra burst of flavor.

Storage Tips:

  • Leftover quiche can be stored in an airtight container in the refrigerator for up to 3 days.
  • To reheat the quiche, simply place it in a preheated oven at 350°F (175°C) for about 10-15 minutes, or until warmed through.


Vegetarian option:

  • For a vegetarian version, you can omit the mushrooms or substitute them with your favorite vegetables, such as spinach, bell peppers, or zucchini.

Gluten-free option:

  • To make this quiche gluten-free, simply use a gluten-free all-purpose flour blend for the crust. You can usually find these blends in your local grocery store or online.

Delicious Caramelized Onion and Mushroom Quiche Recipe

Serving Suggestions

Brunch ideas:

  • This caramelized onion and mushroom quiche is perfect for brunch gatherings. Serve it alongside a variety of other dishes, such as a fresh fruit salad, crispy bacon or sausage links, and a basket of warm bread or croissants.

Side dish options:

  • If you’re serving the quiche as a main course, pair it with a side salad or roasted vegetables. For a lighter side, a mixed green salad with a simple vinaigrette dressing is a great choice. If you’re looking for something heartier, roasted potatoes or steamed asparagus make delicious accompaniments.

Nutritional Information

The nutritional information for this caramelized onion and mushroom quiche may vary depending on the specific ingredients used and the size of the servings. However, as a general estimate, here is a breakdown of the approximate nutritional values per serving:

  • Calories: 400
  • Fat: 28g
  • Carbohydrates: 28g
  • Protein: 10g
  • Fiber: 2g
  • Sugar: 3g

Please note that these values are just an approximation and can vary based on the specific ingredients used and the method of preparation.


Whether you’re hosting a brunch or simply looking for a delicious and satisfying meal, this caramelized onion and mushroom quiche is sure to impress. With its buttery crust, savory filling, and caramelized onions, every bite is packed with flavor. Plus, you have the option to customize the quiche to your preferences by adding or substituting vegetables. So gather your ingredients, follow the simple instructions, and enjoy a homemade quiche that will leave your taste buds wanting more.