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Tomato, Basil & Caramelized Onion Quiche

July 5, 2024

Combining a creamy egg base with heirloom tomatoes, fresh basil, a shaving of Parmigiano-Reggiano, and onions caramelized to perfection, this is the be-all end-all of quiche recipes.

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tomato basil and caramelized onion quiche with two slices cut out of it shown with a sharp knife.

All Day Eggs.

An Heirloom Tomato Quiche.

Sun-sweetened tomatoes are delicious any which way you slice it, but for us, we love to enjoy their juicy pop in a tomato quiche. Add garden-fresh basil, sweet Caramelized Onions, and a shaving of Parmigiano-Reggiano and you get our favorite summer breakfast quiche. IF you have extra tomatoes in the garden try our Chicken Caprese or our Best Tomato Salad!

Tomato slices, fresh basil, sweet onion slices, garlic, butter, flour, eggs and heavy cream in small bowls and plates

What Is Quiche?

Our definition of “quiche” is simply a savory pie crust (aka, pate brisse) filled with an eggy custard. For food history buffs, here’s a tasty tidbit: quiche originated in the Alsace-Lorraine region of France, and it’s most popular iteration—Quiche Lorraine—is filled with bacon, Gruyère cheese, and heavy cream. We’ve taken that classic quiche recipe and transformed it into a vegetarian celebration of all things summer. Here’s how:

  • We’ve swapped quiche Lorraine’s classic bacon for umami-rich caramelized onions.
  • Add summertime seasonal ingredients like juicy heirloom tomatoes and fragrant, fresh basil.
  • Sprinkle with freshly grated Parmigiano-Reggiano.
yellow onion slices, salt and brown sugar in a skillet
yellow onions caramelized in a skillet with a wooden spoon
pie crust shaped into a pie dish
raw pie dough filled with caramelized onions and garlic

How to Make Quiche

Our quiche recipe is pretty much foolproof, thanks to the fact that most of the mixing happens in your trusty food processor. Adding caramelized onions is an easy way to add tons of flavor, while still making this a vegetarian quiche recipe.

  • Start by adding thinly sliced onions to a hot frying pan bubbling with butter and brown sugar and cooking down until the onion slices collapse onto themselves and take on a deep, dark mahogany hue.
  • While the onions caramelize, make the quiche crust by pulsing together flour, salt, and frozen butter in your food processor. Add water at a slowwww trickle until the dough just comes together. The more water you add, the more the crust will shrink when it bakes, so less water the better.
  • Layer your heirloom tomatoes, cheese, fresh basil, and sweet caramelized onions into the crust. Pour in eggs and fresh cream, and bake until the center loses its wobble!
  • Serve your tomato-laden, caramelized onion quiche alongside our Simple Butter Lettuce Salad and call it breakfast well done (or dinner, if you please!).
par-baked pie crust filled with caramelized onion and sliced tomatoes
raw pie crust filled with sliced caramelized onions, sliced tomatoes and topped with parmesan cheese and fresh basil
tomato, fresh basil and caramelized onions in a raw pie crust with egg and cream mixture
Tomato, basil and caramelized onion quiche in a ceramic pie dish

How to Store Leftovers + Tips

  • Can You Freeze Quiche? Yessss!! Maybe your friend just had a baby, or your tomato plant is so weighted down with burtingly ripe tomatoes it can barely stand upright. No matter the reason, bake this egg quiche ahead of time, let completely cool, then wrap tightly in a few layers of cling wrap, and freeze. When you’re ready for a little slice, simply pop the still-frozen quiche in a preheated oven at 350°F for about 20-30 minutes, or until it is heated through.

  • Frittata vs. Quiche—What’s the Diff? The easiest way to remember? Quiche = crust. Frittatas typically omit the crust and heavy cream, relying mostly on the eggs.

  • Store in an airtight container in the refrigerator for up to 1 week. Enjoy heated up, cold or room temp!
tomato, basil and caramelized onion quiche topped with parmesan in a ceramic pie pan
tomato, basil quiche on a marble counter with two slices cut out of it shown next to a knife and linen

Tools You’ll Need to Make This Easy Quiche Recipe:

  • Sharp knife.

  • Food processor. Ours sees so much action we stopped even trying to put it away. Now it just lives in its happy little place on our counter, and honestly we don’t mind one bit.

  • Quiche pan or pie pan. You don’t have a quiche pan?! Not to worry—a regular 9-inch pie pan will do.

Love Eggs? Here Are More Eggy Recipes We Love:

Seriously, we could eat eggs for every meal of the day. You, too? Take these egg recipes out for a spin:

Find More Great Dinner Ideas From The Modern Proper

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Tomato, Basil & Caramelized Onion Quiche

  • Serves:  8
  • Prep Time:  1 hr
  • Cook Time:  1 hr
  • Calories:  319

Ingredients

  • 1 tablespoon salted butter
  • 1 medium yellow onion, halved and thinly sliced
  • 1¼ teaspoon sea salt
  • 1 teaspoon brown sugar (optional)
  • 2 garlic cloves, minced
  • 1 unbaked Pie Crust, homemade or store bought
  • 6 large eggs
  • ¾ cup heavy cream
  • ½ teaspoon freshly cracked black pepper
  • 12 ounces assorted tomatoes, cut into ¼-inch-thick slices
  • 8 fresh basil leaves, thinly sliced, plus more for serving
  • ⅔ cup grated Parmesan

Method

  1. In a medium nonstick skillet, heat the butter over medium heat. Once the butter is melted, add the onions and cook, stirring often, until softened and translucent, about 10 minutes. Season with ¼ teaspoon of the salt and the brown sugar, if using. Reduce the heat to medium-low, spread the onions into a single layer, and cook, stirring every 10 to 15 minutes, then returning the onions to a single layer, until the onions are golden brown and caramelized, about 45 minutes total. If the onions are browning too quickly, add water, 1 tablespoon at a time, until they stop browning and return to caramelizing. Add the garlic and cook until fragrant, 5 minutes longer.

  2. Meanwhile, preheat the oven to 375º F with a rack in the center position. Gently press the prepared pie dough into a 9-inch pie or quiche pan. Using a fork, poke holes all over the crust. Bake for 20 minutes. Remove from the oven and set aside.

  3. Add the eggs, heavy cream, remaining 1 teaspoon salt and pepper in a food processor or blender, and blend until smooth, 1 minute.

  4. Add the onions to the par-baked crust, layer with the tomatoes and then top with the basil and ½ cup of the Parmesan. Pour the egg mixture over the tomatoes. Bake until the egg mixture is set and just barley jiggles, about 35-40.

  5. Sprinkle with remaining parmesan and basil. To serve, cut into 8 wedges. Store in an airtight container, refrigerated for up to one week or frozen for 1 month.

Nutrition Info

  • Per Serving
  • Amount
  • Calories 319
  • Protein 10 g
  • Carbohydrates 20 g
  • Total Fat 21 g
  • Dietary Fiber 2 g
  • Cholesterol 188 mg
  • sodium 256 mg
  • Total Sugars 2 g

Tomato, Basil & Caramelized Onion Quiche

Questions & Reviews

Join the discussion below.

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  • Ryan

    Can I use milk instead of cream?

    Cream will give you the best result. We haven't tested with milk to confirm the consistency will hold up.

  • Erin

    How many cherry tomatoes (or what weight of cherry tomatoes) would you sub for the medium tomato?

    You could use between 4-6 ounces of cherry tomatoes. Hope you enjoy!

  • Carolyn

    I am going to use premade crust in pan
    do I follow the recipe from that point and just put it in the crust to bake. It was mentioned that the crust becomes wet . How do you eliminate that problem??
    Can you use grape tomatoes ??? I just dont want the quiche crust to be wet

    Yes ma'am just ignore any instructions for making your own crust. As for a wet crust we haven't noticed this problem but you can use grape tomatoes or after slicing your tomatoes place them in a strainer before going into the pie crust.

  • Megan

    If you were going to use pre made pie crust, do you make it exactly as listed? Or pre cook the crust? Thanks!!

    No need to pre-cook the crust, hope you enjoy Megan!

  • eileen

    I'm confused about quantity of tomatoes. The pictures imply several tomatoes sliced but the ingredient list calls for one chopped. Which is correct? Thank you.

    It is One chopped, thanks Eileen!

  • Heather

    BEST QUICHE IVE EVER MADE. Its not your easy throw together kind of quiche but man is it worth every step. Huge crowd pleaser and I make it for all my guests!

    THANK YOU HEATHER! This is so wonderful to hear, we are so happy you love it!

  • Elizabeth

    I just made this for a brunch and my favorite review was someone remarked didn't think he liked quiche until he had a bite of this one. And, I used a homemade pie crust with a teaspoon of dried Thyme added.

    AMAZING! So happy it was a hit Elizabeth!

  • CAROL

    This is by far one of the best quiche recipes I've ever made! I used a premade refrigerated pie crust. Also put 8 oz. diced ham in the bottom. My husband and I both REALLY loved it. This recipe is going into my "keeper" recipe box.

    Thank you Carol, we are so glad you both loved it!

  • Hannah

    INCREDIBLE. So flavorful and the perfect texture of egg mixture and crust. Will make again.

    thanks Hannah, so happy you loved it!

  • Amy

    We used what we had on hand - yellow onion instead of sweet onion and Campari tomatoes instead of heirloom tomatoes, and this came out absolutely delicious. It was very easy to make, and we had everything on hand for a last minute Easter brunch. I plan on making this for Mother’s Day as well. Soooo good!!!

    Thank you so much Amy, we are so happy that you loved it!