Baked Caramelized Mushroom, Onion, Spinach, and Swiss Cheese Frittata
I like making frittatas on Sunday mornings so I can have quick, healthy, and easy breakfasts for a few days during the week. They are so easy to make, can use up whatever you have in the refrigerator, and are a healthy way to start your day. I found some mushrooms, onions, spinach, and Swiss in the fridge so that’s what I used in this frittata but it would also be good with bacon, ham, or sausage in there too.
How to Make a Baked Caramelized Mushroom, Onion, Spinach, and Swiss Cheese Frittata
Preheat the oven to 350 degrees. Coat a tart pan with cooking spray.
Heat the olive oil in a large skillet over medium-high heat. Add the onions and mushrooms then cook stirring often until caramelized, about 15-20 minutes. Add the spinach to the skillet then season with sea salt and freshly cracked pepper, to taste. Toss until well combined.
Place some of the mushroom & onion mixture and Swiss cheese into the bottom of the tart pan. Combine the eggs with the milk then season with sea salt and freshly cracked pepper, to taste. Whisk the eggs until they are mixed thoroughly.
Pour the egg mixture into the tart pan then add the remaining onion mixture and Swiss cheese to the top.
Ingredients
- 1 tbsp of olive oil
- ½ sweet yellow onion chopped
- 8 oz button mushrooms sliced
- 2 cups of baby spinach
- ¼ cup Swiss cheese diced
- 8 eggs
- 2-3 tbsp milk
- Sea salt and freshly cracked pepper to taste
Instructions
- Preheat the oven to 350 degrees. Coat a tart pan with cooking spray.
- Heat the olive oil in a large skillet over medium-high heat. Add the onions and mushrooms then cook stirring often until caramelized, about 15-20 minutes. Add the spinach to the skillet then season with sea salt and freshly cracked pepper, to taste. Toss until well combined.
- Place some of the mushroom & onion mixture and Swiss cheese into the bottom of the tart pan. Combine the eggs with the milk then season with sea salt and freshly cracked pepper, to taste. Whisk the eggs until they are mixed thoroughly.
- Pour the egg mixture into the tart pan then add the remaining onion mixture and Swiss cheese to the top.
- Place into the oven and bake for 20-25 minutes, or until a tester inserted in the center comes out clean. Let the frittata cool for a few minutes before slicing and serving. Enjoy.
Awesome frittata, Pam. I need to get some mushrooms to make this today!
Looks awesome!!
Pam- I have said this many times, but it’s true. You are the QUEEN of frittatas and baked eggs recipes! Seriously, every recipe I have tried is always delicious! This recipe is no exception and I can’t wait to try it!
Planning ahead for weekday mornings is always brilliant.
What a delicious and versatile breakfast, lunch, brunch or dinner. Love it!
All the veggies I like in a frittata. Looks delicious. I like having leftovers also. They taste just as good a fws days later as they did the first day.
Hermoso y saludable me encanta la espinaca,abrazos
I made a pretty boring fritatta last week so now I feel like i should make up for it with something like this!
Looks like a yummy way to enjoy a spring breakfast or brunch!
It’s in the oven, but looks and smells great! Thanks for sharing. Love your philosophy, organic, low fat.
Just made but switched it up and added bacon.
I’ll let my a know how it tastes
BTW made this with gluten free crust!
Lovely recipe! We didn’t have spinach. So, I swapped in two small sweet red peppers, chopped. I used Jarlsberg for the cheese cubes and sprinkled finely shredded Swiss throughout the eggs because we just love cheese. Mine could’ve used a touch more salt. Next time, I may add crushed bacon… Yum! This recipe is definitely going into rotation.
One tip: if you have a lollipop type cooking thermometer, you’ll know it’s perfectly done when it reaches 185-195°.
Dilly,
I’m so glad you liked the recipe–your changes sound wonderful.
-Pam