Another Crustless Quiche:  Caramelized Onion, Leek and Mushroom with Red Pepper and Fontina

I’m a huge fan of the crustless quiche. I’ve already shared several versions here on the site with this Sheet Pan version, Spinach Pie, Leek & Swiss/Gruyere and Asparagus and Feta. Not having to make a crust not only means less work and more quiche making ability at a moment’s notice, but also results in a lighter, more warm weather friendly brunch, lunch or dinner treat. And this version, full of caramelized onions, leeks, mushrooms, red pepper and fontina cheese, is a terrific new one to add to the repertoire. So we are just going to pretend that there is not half a foot of snow on the ground with bone-chilling temperatures, ok? Because I think that in order to bring on the warmer weather, we are collectively going to have to start cooking as if it’s 60º and sunny. Who’s with me?


All warm weather thoughts aside, this quiche would honestly be great at any time of year. The flavor is really amped up by the caramelizing of the onions, leeks and mushrooms which takes a little bit of time, but is so, so worth it. We all know that caramelized onions just make life better, right?


Anyhow, once all the veggies are cooked, you dump the whole shebang into a pie plate that’s been coated with a little panko (ever since these meatballs, I am so into the panko lately).


And top with lots of lovely shredded, creamy Fontina cheese which melts gorgeously, but of course you could use any cheese you prefer.  Crustless quiches are the epitome of versatility, another reason they are so lovable!


All that’s left to do is pour on the egg/milk/cream mixture and bake.


Easy, delicious and satisfying but not heavy. Perfect for right now…or an outdoor brunch or light summer dinner. We can dream, can’t we?

Another Crustless Quiche:  Caramelized Onion, Mushroom, Red Pepper and Fontina

Makes 6-8 servings

Prep Time:  30 minutes (most of this is hands-free); Bake Time:  30-35 minutes


  • 2-3 tablespoons panko

  • Olive oil

  • 1 large onion, halved and cut into thin half moons

  • 3 leeks, halved and cut into thin half moons, rinsed well in a colander and patted dry

  • 8 ounces mushrooms, thinly sliced

  • 1 red bell pepper, seeded and thinly sliced

  • Kosher salt and black pepper

  • 6-8 ounces shredded cheese (I used Fontina)

  • 4 large eggs

  • 2 cups whole milk or use 1 cup milk, 1 cup half and half or heavy cream for a creamier filling

The Recipe

1.  Preheat oven to 425º F. Spray a pie plate or quiche pan with nonstick cooking spray and coat with the panko. Tap out any excess and set the pan aside. 

2.  Heat a large heavy skillet over medium low heat and add some olive oil just to coat the bottom. Add in the onion, leeks and mushrooms and let cook for about 25 minutes, stirring every so often and turning down the flame if they are cooking too fast. You want them to cook long and slow to caramelize, not burn. Add the red pepper and let cook for about 5 minutes more, until softened. Add a pinch or two of salt and pepper and scrape into the prepared dish. Scatter the cheese across the top.

3.  While the veggies are cooking, whisk the eggs, milk (and cream if using) and another pinch or two of salt and pepper together  and pour the mixture over the veggies and cheese. Place the dish on a rimmed baking sheet 

4.  Bake the quiche for about 30 minutes, I the custard is set and the top is golden. Let sit for a bit if you want neater slices.


Note:  Recipe adapted from What’s Gaby Cooking by Gaby Dalkin. I tinkered with some ingredients and proportions —this is a very versatile recipe, feel free to add in or change anything you like.

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