This post may contain affiliate links. Click here for my affiliate disclosure. If you purchase items through my affiliate links, I receive a small commission but your price doesn't change.
This low carb zucchini quiche is a healthy remake of a recipe I grew up eating a lot! It features a yummy crust with a thin layer of mustard, lots of sliced zucchini in a flavorful custard, and sharp cheddar cheese. THM S
The original zucchini quiche recipe
This zucchini quiche page has existed here on my website since July 2014, but previously it only linked to a recipe from Quick Cooking magazine. This summer I noticed that the link was no longer working, so I decided now would be a good time to create my own zucchini quiche recipe based on the recipe I grew up making, but with a few tweaks of my own.
One unique feature of the old quiche recipe was a layer of yellow mustard on the crust. Sounds strange, I know, but weirdly – it works.
Take 5
To recreate this recipe, I gathered ideas from my memories of the old Quick Cooking recipe but used this Mushroom & Ham Quiche as my starting point.
The original zucchini quiche recipe used two 9″ pie crusts. I decided to remake the recipe in a 9″ x 13″ pan with a press-in low carb crust. I made this zucchini quiche about 5 times before getting it perfect. The crust was a challenge – sometimes it resembled sawdust and sometimes it came out soggy. Finally I got it right – or as good as I can get it, at least.
The pictures in this post are actually from Take 3 or 4. I improved this recipe in a few ways (made the quiche less dense and the crust less dry, mixed the cheese in instead of layering it over and under the custard mixture) since photographing it, but I didn’t feel like redoing the pictures. If you want the quiche to look like the pictures here, you can put part of the cheese on top of the quiche before baking instead of mixing it all into the custard.
Optional garnishes
You can garnish the top of the quiche with additional shredded cheese, a sprinkling of smoked paprika, and/or thinly sliced tomato rounds before baking if you like!
How to make a crustless zucchini quiche
Simply omit the crust. It works great. You can stir the mustard into the custard mixture or omit it entirely.
Can I use other veggies in this zucchini quiche?
I don’t see why not! Some tips:
- Use only non starchy veggies.
- Use them in place of the same quantity of zucchini.
- Sauté until tender and drain excess liquid as directed before stirring into the custard mixture.
As always, check out the Notes section of the recipe for helpful info and answers to frequently asked questions!
You may also enjoy:
-
STARTING THM
-
MY RECIPE INDEX
-
RECIPE INDEX BY FUEL TYPE/ALLERGY/THEME
-
Fried Breaded Zucchini
-
Zucchini Bars
60+ Healthy Summer Squash Recipes
Are your zucchini plants taking over your garden (and eating up all your fridge space)? Check out this post with tons of THM friendly summer squash recipes!

Zucchini Quiche
- Total Time: 1 hour 18 minutes
- Yield: 10 servings
Description
This low carb zucchini quiche is a healthy remake of a recipe I grew up eating a lot! It features a yummy crust with a thin layer of mustard, lots of sliced zucchini in a flavorful custard, and sharp cheddar cheese. THM S
Ingredients
CRUST
- 1/2 cup (53g) coconut flour
- 1/2 cup (37g) oat fiber
- 2 eggs
- 6 tablespoons salted butter (melted)
- 2–3 tablespoons yellow mustard
CUSTARD
- 1 tablespoon salted butter
- 1 medium onion (215g)(chopped)
- 8 cups (800-1000g) thinly sliced zucchini (You can use green and/or yellow zucchini. Cut the rounds into halves or quarters if large.)
- 12 eggs
- 1/2 cup half and half (or try heavy cream or unsweetened almond milk)
- 1 1/2 teaspoons garlic powder
- 1 1/2 teaspoons salt
- 1 teaspoon Italian seasoning
- 1/2 teaspoon black pepper
- 1/2 teaspoon dill weed
- 2 cups finely shredded sharp cheddar cheese
Instructions
- CRUST: Mix the crust ingredients together with a meat fork or hand mixer. (The texture will be like Play-Doh.) Press into the bottom of a greased 9”x13” glass pan and prebake for 8 minutes at 350*F. When the crust is done baking, remove it from the oven and brush it with 2-3 tablespoons of yellow mustard. (I use a pastry brush.) You just need enough mustard for a thin layer over the crust.
- CUSTARD: Sauté the onion and zucchini in the butter in a pan until tender. I cover the pan with a lid to hasten the cooking process but leave the lid cracked open to let moisture evaporate. When the veggies are tender, drain the excess liquid and let the veggie mixture cool a bit so it doesn’t scramble the eggs in the custard.
- Whisk the eggs, half and half, and seasonings together. Stir in the shredded cheese. Add the cooled onion/zucchini mixture and stir until homogenous. Pour the custard mixture over the prebaked and mustarded crust.
- Bake at 350* for 35-40 minutes or until set. Let cool at least 10 minutes (to firm up) before cutting and serving. Salsa and sour cream to accompany the quiche would be great!
Notes
You can garnish the top of the quiche with additional shredded cheese, a sprinkling of smoked paprika, and/or thinly sliced tomato rounds before baking if you like.
To make a crustless quiche, simply omit the crust. It works great. You can stir the mustard into the custard mixture or omit it entirely.
Can I use veggies other than zucchini? That should work! 1) Use only non starchy veggies. 2) Use them in place of the same quantity of zucchini. 3) Sauté until tender and drain excess liquid as directed before stirring into the custard mixture.
Oat fiber: This versatile low carb flour can usually only be found online. Not all brands are created equal, but I like LifeSource oat fiber. Use gluten free oat fiber for a gluten free option. Oat fiber and oat flour are different and are not interchangeable.
I made this zucchini quiche about 5 times before getting it perfect. The pictures in this post are actually from Take 3 or 4 and the recipe as written may come out looking slightly different. I didn’t feel like rephotographing it, sorry. If you want the quiche to look like the pictures here, you can put part of the cheese on top of the quiche before baking instead of mixing it all into the custard.
Allergy info: Gluten free (use gluten free oat fiber). Nut free.
- Prep Time: 30 mins
- Cook Time: 48 mins
- Category: Main Dishes
- Method: Baked
- Cuisine: THM S, low carb, gluten free, nut free
Keywords: trim healthy mama, thm, low carb zucchini quiche, low carb quiche recipe, thm zucchini recipes, zucchini quiche recipe
I am wanting to know if I could have the original zucchini quiche in Taste of Home that was linked before. It was such a favorite!, Really missing it! Tried this one as well and very good
I’m sorry – one of the reasons I updated this post with my own recipe was that the original link from Taste of Home wasn’t working and I couldn’t find that recipe anymore.
I made this tonight (it was delicious!) but I may have eaten too much! Any idea how many servings this should actually be.
A 9″ pie plate is usually 6-8 servings, but it all depends on what else you had with it. 🙂 As long as you eat until you’re satisfied but not stuffed, you should be fine.
I can’t wait to try this, but i’m looking for low carb & low cholesterol recipes
Love “Necessary Foods.” So many great and easy recipes. Thank you for publishing it.
Thank YOU for buying it! I’m so glad you like it!
So I’m used to quiche recipes using a bit of liquid in with the eggs… how did this recipe pan out (ha) with no real liquid? Was the quiche really firm? We like a more springy quiche, so perhaps almond milk?
We’ve been making it for years and love it! I’ve never used a quiche recipe with milk or other liquid in it and I imagine that would make it very soupy. In this case, the fresh veggies add a lot of juice themselves, so I wouldn’t recommend adding any more. I wouldn’t say it’s really firm.