This post may contain affiliate links that won’t change your price but will share some commission.

Zucchini Caramelized Onion Quiche, delicately-flavored zucchini pairs perfectly with caramelized onions and gouda cheese. This satisfying quiche recipe is perfect for fuss-free, easy breakfasts, dinners, and lunches.

A delicious quiche can be made with almost any combination of veggies and using store-bought pie pastry makes it ultra simple to prepare.

Zucchini Caramelized Onion Quiche


Quiche is really underrated. Quiche is a great way to use leftovers. It’s my go-to Thursday night meal when I haven’t planned anything or have leftovers from the week. Corn, mushrooms, peppers, zucchini, squash, and onions all make great additions to quiche. As well, leftover breakfast meat sausage, ham, or bacon are all good in quiche.

Not to mention, if you watch how much and what kind of cheese you use and go crustless, quiche can be healthy. It’s full of protein and nutrients from vegetables. 

It’s also so simple to make. Plus, I find a flaky pie crust hard to resist. 


  • Cover a pizza pan or cookie sheet with aluminum foil then place your quiche on it. As a result, any overflows will land on the cookie sheet, not your oven. It’s also easier to get the quiche in and out of the oven.
  • Blind Bake your crust.
  • Use a mandoline to slice your zucchini.
  • You really need to saute the zucchini before mixing it with the eggs. Otherwise, it will release too much water. As well, it probably won’t get done if it’s not cooked a little beforehand. It really takes less than 10 minutes to cook the onions and zucchini so go ahead and get them started while your oven is preheating.

one dish meal

How to slice zucchini

If you don’t have a mandoline slicer, it’s time to make a purchase. Seriously, you can perfectly slice zucchini, potatoes, anything as thick or as thin as you want it.

You really don’t have to spend a lot on a good mandoline. However, you do need to use extreme caution when slicing with it. They have very sharp blades. Never touch the blades. Never slice anything without the gloves on or without the food safety holder

Make this Zucchini Caramelized Onion Quiche KETO

  • To lower the carbs, you need to omit the crust. Butter your 9-inch or 8-inch pie plate to prevent sticking and you’re good to go.
  • Gouda cheese is low in carbs or you can sub any low-carb cheese.
  • White and red onions aren’t considered keto-friendly. Personally, I feel that carbs that come from natural ingredients like fruits or vegetables are good for you. However, if you don’t, you can substitute green onions or omit onions altogether.

eggs and veggies

What Is Blind-Baking?

I recommend you blind-bake the crust to keep it crispy. Blind baking is the process of baking a pie shell or crust without the filling. Above all, blind-baking ensures a crisp crust. Otherwise, the crust tends to get gummy and not bake through if you add the filling before baking it.

How to Blind-Bake a pie crust

  1. Fit your rolled-out dough into a pie pan, gently pressing it into the ridges with your fingers. Trim or fold the excess, then crimp.
  2. For this recipe, you can use my Coconut Oil Pie CrustNever-Fail Pie Crust, or a premade, purchased deep dish pie crust.
  3. Line the pie crust with a sheet of parchment paper then fill with either pie weights or dried beans. This will keep the crust from forming a big bubble in it.
  4. Next, bake in a 350°F oven for 7 minutes.
  5. Remove the weights and parchment, and bake for another 3 to 5 minutes until the bottom of the crust has just begun to brown.
  6. Finally, all the crust to cool for about 5 minutes before adding the filling.

Zucchini Caramelized onion Quiche

How to freeze quiche

 You can make it ahead and refrigerate or freeze it for later. Quiche can be frozen prior to baking or after baking; baking first may make the quiche a little easier to maneuver in the freezer.

To freeze quiche before baking: Place quiche on a tray or baking pan and freeze until firm. Wrap with freezer paper or heavy-duty aluminum foil or slide quiche into a freezer bag. Seal, label, and freeze for up to one month.

When ready to serve, remove from the freezer. Do not thaw. Unwrap and bake, as usual, adding 10 to 20 minutes extra time.

To freeze quiche after baking: Proceed as above. Do not thaw before reheating. Remove wrap and bake in a preheated 350°F oven for about 25 minutes, or until heated through.

Zucchini Caramelized Onion Quiche recipe

You’ll like these recipes too

  1. Cream Cheese Sausage Rotel Dip Quiche
  2. Bacon and Sausage Quiche
  3. Fluffy Cottage Egg Casserole
  4. Bacon Havarti Quiche
  5. Cauliflower Mushroom Leek Crustless Quiche
  6. Vidalia Onion Pie 
  7. Cheesy Garlic Spaghetti Squash
  8. Panera Bread Ham and Swiss Souffle 

Last But Not Least…if you make this recipe please leave a rating and a comment if you don’t mind. I love hearing from you. And post a photo of your quiche on Instagram and tag me, @Paula_callmepmc!

Zucchini Caramelized Onion Quiche


A delicious recipe for your abundance of summer zucchini. This quiche is quick and easy. It freezes well, see post for details on freezing.
Author: Paula
5 from 11 votes
Print Rate

Want to save recipes? Create an account or login & then you can use the “Save Recipe” button when viewing a recipe to save it to your Recipe Box. You can access your saved recipes on any device and generate a shopping list for recipes in your collections.

Save To Your Recipe Box
Prep Time: 10 minutes
Cook Time: 30 minutes
Servings: 8 servings


  • 1 9-inch pie crust
  • 1 medium zucchini sliced thin
  • 1 small onion sliced thin
  • 2 tablespoons red bell pepper diced
  • 1 tablespoon avocado oil
  • 5 large eggs
  • ½ teaspoon salt
  • ½ teaspoon thyme
  • teaspoon dried dill
  • ¼ teaspoon freshly ground black pepper
  • cup heavy cream
  • 2 tablespoons parmesan cheese freshly grated
  • 1 and ½ cup Gouda cheese grated


  • Preheat your oven to 350°F. Place the pie pan on a larger sheet pan to catch any spills. (any pan will work but it should have an edge to catch overflows.) After the oven is preheated, blind-bake your pie crust until lightly browned about 10 minutes. (How to blind bake instructions in the post above, if needed.)
  • Thinly slice the onion and zucchini and dice the bell pepper. Saute them along with the salt, pepper, dill, and thyme in 1 tablespoon of avocado oil until the vegetables are soft. (heating the seasonings brings out the flavor.)
  • Remove from the pan and spread evenly in your pie crust.
  • Sprinkle the gouda and parmesan cheese over the zucchini mixture.
  • Meanwhile, in a bowl, whisk the eggs until fluffy.
  • To the eggs, add the heavy cream and stir.
  • Pour the egg mixture over the zucchini, onions, peppers, and cheese.
  • Bake at 350°F for 25 to 30 minutes until set in the center and lightly brown on top.
  • Remove from the oven and allow to cool for 5 minutes before cutting and serving.
  • Store any leftovers in an airtight container in the refrigerator for up to 3 days. See post above for freezing instructions.


Calories: 380kcal | Carbohydrates: 15g | Protein: 18g | Fat: 27g | Saturated Fat: 14g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 10g | Trans Fat: 0.01g | Cholesterol: 179mg | Sodium: 680mg | Potassium: 215mg | Fiber: 1g | Sugar: 2g | Vitamin A: 703IU | Vitamin C: 8mg | Calcium: 361mg | Iron: 1mg
Tried this recipe?Please take a moment to comment letting me know how you liked it & consider giving it a 5 star rating. I love hearing from you!
Do you have questions about saving recipes to your Recipe Box?Visit Recipe Box FAQ!

Leave a Reply

Your email address will not be published. Required fields are marked *

Your email address will not be published. Have you tried this recipe? Consider giving it 5 stars!