This Crustless Zucchini Quiche is made with tender zucchini, perfectly caramelized onions and fresh herbs in a delicious cheese and fluffy egg filling.

❤️ Why You’ll Love this Crustless Quiche Recipe

• Layers of tender zucchini, caramelized onions, fluffy eggs and cheese
• Hearty and filling
• No need to make a pie crust
• Great for meal prep
• Easy to prepare

Of course, quiche is the quintessential brunch food, but this easy cheesy recipe is great for any meal of the day. Loaded with layers of vibrant and delicious zucchini, and sweet caramelized onion, this simple yet elegant quiche recipe makes a complete meal as is or served with a tossed salad or a side of fresh fruit.

Because it's crustless, this quiche is not only absolutely delicious, but it's also very low in carbs and it's gluten-free, perfect for Keto or low carb diets. It's a healthy, protein packed meal that will leave you feeling satisfied for hours.

If you'd like to try this quiche recipe in a crust, you can add the filling to this baked Homemade Keto Pie Crust.

🛒 What’s in Keto Crustless Quiche

• Zucchini
• Cheddar cheese
• Eggs
• Heavy cream
• Yellow onion
• Butter
• Fresh parsley
• Olive oil
• Dried thyme
• Salt
• Ground black pepper

*Exact measurements are listed in the recipe card below.

🥣 Recommended Tools

• Large skillet

🔪 How to Make Crustless Quiche

Preheat oven to 350°F.

Add the eggs in a large mixing bowl, along with the heavy cream, thyme, parsley and half the salt and pepper.

Mix using a hand mixer or whisk until well combined and frothy.  Set aside while you sauté the veggies.

Tip: Whipping up the eggs helps make them light and fluffy.

Add the butter and olive oil to a large skillet and once melted, add in the zucchini, half the remaining salt and pepper, then sauté until cooked through.

Remove the zucchini and set aside to drain on paper towels.  Add in the onions and the remaining salt and pepper, then sauté until translucent.

Tip: Sauté the zucchini and onions until slightly caramelized. This helps give them more flavor.

Take a pie dish that’s been sprayed with nonstick spray or brushed with olive oil and arrange half the zucchini on the bottom. 

Add the onions and half the cheese.

Pour the egg mixture over the top.

Add the rest of the cheese, then arrange the remaining zucchini on the very top.

Bake for 30 minutes or until the eggs have fully set. Allow to cool slightly before cutting and serving.

Tip: When you first remove the quiche from the oven, they will be very puffed up, then will deflate within a few minutes. This is completely normal.

How Long Will a Crustless Quiche Keep in the Fridge?

As long as you keep it covered well with plastic wrap or in an airtight container in the fridge it should stay fresh for 2-3 days.

Why is My Zucchini Quiche Watery?

There are several reasons homemade quiche can turn out a little too watery. Here are the most common causes:

• Overbaking: It sounds crazy, but overbaking your quiche can cause the proteins in the eggs to start bonding and separating from the liquids. The liquids will settle in pockets making the quiche runny.

• Underbaking: Though you don’t want overbaked quiche, you do want the quiche to cook long enough for the eggs to set up so that they’ll be firm and safe to eat. The actual cooking time will vary based on the size of your eggs.

• Egg to dairy ratio: One of the most obvious causes is that you used too much heavy cream. Quiche is an egg forward dish, meaning the dairy is secondary to the number of eggs you’ll use.

• Veggies: Most vegetables contain a lot of water. If you add them directly to the egg mixture raw, as the quiche bakes, the moisture will release resulting in a runny quiche.

Variations and Substitutions of Crustless Quiche

The ways you can prepare quiche is endless. For this recipe, here are some fun and tasty options to change it up:

• Cheese: Cheddar is also a great choice, but you can use Swiss, Monterey jack, pepper jack or any melty cheeses. You can also add in some fresh grated parmesan for a tangy bit of flavor.

• Veggies: Feel free to add other sautéed vegetables. Mushrooms, bell peppers, roasted red peppers and asparagus tips are all great options.

• Additional protein: Though perfect for meatless Mondays, you can always add additional protein with ground sausage, cooked bacon, or shredded chicken.

Do You Pre-Cook Vegetables for Quiche?

Pre-cooking the zucchini is essential for the perfect quiche. This allows most of the moisture to cook out before adding them to the other ingredients.

Is Zucchini Keto?

Zucchini is a great vegetable for Keto. It contains many wonderful vitamins and minerals like, vitamin A, manganese, vitamin C and potassium.

It's also low carb! The carbs in zucchini are especially low because it's made up of mostly water. For a one cup serving, there are 4 total grams of carbs, which when you minus out the fiber, there's only a little over 2 net carbs in zucchini.

Be sure to also check out these recipes using zucchini:

• Keto Zucchini Fritters
• Keto Zucchini Lasagna
• Buffalo Zucchini Boats
• Zucchini noodle "pasta" salad
• Chocolate Zucchini Muffins
• Lasagna Zucchini Boats

What's the Difference Between Quiche and a Frittata?

• Most of the time quiche filling is poured into a crust (unless you’re making a crustless quiche, while a frittata is never prepared in a crust.

• Frittatas start off cooking on the stovetop, then are finished in the oven. Quiches (like this crustless quiche) are baked entirely in the oven.

• Quiches combine cream or milk to give the eggs super fluffy texture. Frittatas often use only eggs or less cream.

More Keto Eggs Recipes

• Easy Breakfast Casserole
• Keto Quiche Lorraine
• Spinach and Sausage Quiche
• Jalapeño Popper Egg Cups
• Mexican Breakfast Casserole
• Smoked Salmon Crustless Quiche