clock clock iconcutlery cutlery iconflag flag iconfolder folder iconinstagram instagram iconpinterest pinterest iconfacebook facebook iconprint print iconsquares squares iconheart heart iconheart solid heart solid icon

Zucchini Quiche


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




  • 23 tablespoons yellow mustard



  • 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


  1. 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.
  2. 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.
  3. 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.
  4. 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!


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