Our zucchini quiche is packed with sauteed summery onions and zucchini. The slightly sweet, caramelized flavor of the vegetables permeates throughout the delicious, cheesy filling of the quiche. Yet the key ingredient in this dish might be the most unassuming: mustard. Just a simple smear of mustard over the crust balances the sweetness of the vegetables and adds a pleasant little zing to each bite.
Among all our quiche recipes, this is one is guaranteed to wow guests at your next brunch, yet it’s simple enough for a weeknight in with the family. Add a crisp salad on the side, and dinner is served!
Ingredients for Zucchini Quiche
- Pie dough: The same basic single-crust dough works for sweet pies and savory quiches (here’s how to make pie crust). If you’re in a rush, you can swap in a store-bought refrigerated or frozen dough. Here’s our Test Kitchen’s picks for the best premade pie crust.
- Zucchini: This is one of the best recipes for zucchini at the height of summer squash season. Zucchini, onion and many other vegetables contain lots of natural water. Precooking and thoroughly draining these ingredients helps to put the brakes on potential sogginess.
- Eggs: For a quiche recipe, there’s a surprisingly small amount of eggs used here. Just make sure the eggs are at room temperature for the best mixing.
- Cheese: Grate your own mozzarella cheese for the best flavor. Here are the best mozzarella cheese brands according to our Test Kitchen pros.
- Mustard: This secret ingredient elevates all the other flavors in the quiche! Try Dijon mustard for a sharper flavor, honey mustard for a sweeter one, or spicy brown mustard for bonus heat.
Step 1: Roll out the crust
Preheat the oven to 400°F. On a lightly floured surface, roll the dough into a rough circle about 1/8 inch thick. Transfer it to a 9-inch pie plate, trim the edge to the rim of the plate, and flute or crimp with a fork.
Refrigerate the crust while you prepare the filling.
Editor’s Tip: To easily transfer the pie dough, roll it up around the rolling pin, set the free edge on one side of the pie plate, and unroll it from the pin across to the other side. Then press it into the bottom of the plate, and trim the edge. If you want to get fancy, here’s how to make decorative pie crusts.
Step 2: Precook the vegetables
In a large skillet, heat the butter over medium heat. Add the zucchini and onion. Cook, stirring often, until tender. Drain the vegetables, and let them cool slightly.
Step 3: Prepare the filling
Whisk the eggs briefly, and whisk in the parsley, salt, garlic powder, basil, oregano and pepper until blended. Stir in the cheese and the zucchini mixture.
Step 4: Fill the crust
Remove the pastry shell from the refrigerator, and spread the mustard over the base. Add the filling, distributing it evenly to the edges.
Step 5: Bake the quiche
Bake the quiche on a lower oven rack for 35 to 40 minutes, until a knife inserted in the center comes out clean and the crust is golden brown. If needed, cover the edge loosely with foil during last 15 minutes of baking to prevent overbrowning. Let the quiche stand for 10 minutes before slicing.
Editor’s Tip: Make a pie crust shield to keep the edges of the quiche from getting too brown. Once out of the oven, letting the quiche stand before slicing is super important. You want the filling to set properly, ensuring a clean slice.
- Vegetable and cheese substitutions: Adding ingredients would change this quiche’s consistency, but you can replace some existing ones. Swap in sauteed mushrooms, roasted garlic or thinly sliced cooked potatoes for some of the zucchini or onion. Or try ricotta, cheddar, Monterey Jack or Gruyere cheese instead of mozzarella.
- Fresh herbs: Chop up fresh herbs for even more flavor in this quiche. Use three times the volume when replacing dried herbs with fresh. For a showy touch, sprinkle some on top as soon as you pull the quiche from the oven.
- Crustless quiche: You can skip the crust altogether for this quiche. Generously grease the pie plate with butter or cooking spray, pour the filling into it, and bake as usual. To keep the mustard tang, spread the prepared mustard directly on the pie plate.
How to Store Zucchini Quiche
You can eat quiche at room temperature, but store leftover zucchini quiche, tightly wrapped or in an airtight container, in the refrigerator for up to three days.
Can you freeze zucchini quiche?
Quiche freezes so well, you’ll always want to have one stashed away for a no-fuss yet fancy breakfast. Bake the quiche, and let it cool completely. Wrap it tightly in plastic wrap, then foil to prevent freezer burn. Stored this way, the whole quiche or individual slices can keep in the freezer for up to three months. Thaw in the fridge overnight, then reheat until a thermometer inserted into the thickest part of the quiche registers 165°.
Zucchini Quiche Tips
How do you keep quiche from becoming watery?
To keep a quiche from becoming watery, cook and drain moisture-rich vegetables like zucchini and onion to remove most of the natural water content. Baking quiche at a fairly low temperature allows the egg to bind to the other ingredients, and excess liquid will evaporate in the heat. To avoid overcooking, pull the quiche out of the oven while the center is set but jiggles slightly. If the quiche still comes out watery, try low-moisture mozzarella next time.
How do you reheat quiche?
To reheat quiche from frozen, let the quiche thaw overnight in the refrigerator then sit at room temperature while you preheat the oven to 350°. Reheat precooked quiche until it is warmed through; an instant-read thermometer inserted in the center will show 165° when it’s ready. You can reheat leftover refrigerated quiche in the oven or the microwave for a few minutes.