This savory caramelized onion and mushroom quiche has a great flavor and is perfect for brunch or a breakfast for dinner meal.
I’m pretty sure you can add caramelized onions to just about anything and instantly improve the dish. They are sweet and tangy, and a little jammy if you cook them right. Combine that with some mushrooms, feta, and thyme and you have a great depth of flavor.
Quiche sounds a little fancy, but couldn’t be easier to make. This vegetarian quiche has great flavor that will please everyone around the table. We’re even tossing in some spinach for extra greens. Making caramelized onions requires a bit of time, but most of it is hands off so you can prep the rest of the quiche while the onions and mushrooms are cooking.
As the mushrooms and onions cook, whisk together the eggs, Greek yogurt, whole milk, dried thyme, salt, pepper, and chopped spinach. Add the mushrooms and onions to the mixture and then pour into the prepared pie dish. After 35-40 minutes in the oven, you’ll have a deliciously easy homemade quiche!
I prefer using whole milk and whole milk Greek yogurt here, it makes for a very creamy quiche. If you want to substitute a lower fat milk, it just may not be as creamy.
Quiche can also be made ahead of time, a huge win for weekend brunches! We often make this on Sunday and have it all week for easy breakfasts that feel a little more substantial than toast and jam, but are just as quick to prepare.
A homemade quiche typically requires a par baked crust which just means you roll out the pie dough into your dish and bake it for 10 minutes before putting the filling in. You definitely need to use pie weights or dried beans for this step or the pie crust will shrink up completely during the 10 minutes in the oven.
Par baking the crust is really the most technical part of this recipe, so don’t let that deter you from trying a homemade quiche for the first time! Also, I definitely just buy my crusts at the store. I firmly believe Thanksgiving is the only time for homemade pie crusts so feel free to take the shortcut here as well.
I hope you try this vegetarian quiche this weekend, and if you do please let me know how it goes! And don’t forget to sign up to receive an email each time there’s a new post. Thanks for stopping by the blog today!
Caramelized Onion and Mushroom Quiche
Sweet and tangy caramelized onions and mushrooms give this quiche a delicious deep flavor. Perfect for pretty much any meal of the day!
- 1 pie crust single 9 inch crust
- 2 tbsp butter
- 1 yellow onion
- 8 oz baby bella mushrooms
- 2 tbsp balsamic vinegar
- 6 eggs
- 1/2 cup greek yogurt
- 1/2 cup whole milk
- 4 oz crumbled feta cheese
- 1 tsp dried thyme
- 1/2 tsp salt
- pepper to taste
- 1 cup spinach roughly chopped, about 1 ounce
Pre-heat the oven to 375. Roll out the pie crust to fit in a 9 inch pie dish. Using parchment paper and pie weights, pre-bake the crust for 10 minutes. I use two sets of pie weights so the crust doesn't shrink, if you don't have pie weights use a bag of dry beans instead.
While the crust is baking, thiny slice the onions and cook them in a large pan over medium heat with 2 tbsp butter. Clean and slice the mushrooms and add them to the onions. Stir occasionally.
While the onions and mushrooms caramelize, whisk together eggs, yogurt, milk, cheese, spinach, and seasonings in a large bowl.
Cook the onions and mushrooms for at least 20 minutes, letting them get golden brown. Add a few splashes of balsamic vinegar to the pan to deglaze it. Cook for another 1-2 minutes then remove from heat.
Place the cooked veggies in the bottom of the par baked crust, then gently pour the egg mixture over top. Give everything a gentle stir and bake in the oven for 35-40 minutes, until the quiche is just set. It can still jiggle a bit and it will be okay.
Let cool 10 minutes before cutting and enjoy!