Caramelized Onion & Mushroom Frittata

The glorious combination of butter, onions, mushrooms, thyme and white wine in a Sunday brunch frittata.

Easter Sunday is nearly upon us. Time to start thinking about a fabulous Easter brunch menu. This mushroom frittata is dressed in its Sunday best after the star ingredient get a little simmer in butter and white wine.

‘Fraid of Fungus?

Are you afraid of mushrooms? I used to be. Raw mushrooms elicit strong reactions. For years the only wild mushrooms I’d cook with were chanterelles. The snob of the mushroom family.

Chanterelle mushrooms


I had fallen in love with chanterelles after being gifted some from a friend who is lucky enough to have them growing wild in her yard. Came up with some good recipes for them. More on that when season hits.

Side story – I was traveling in the Mosel River Valley of Germany and kept seeing “Pfifferlinge” on restaurant special boards. I passed right by them before I remembered that my sister-in-law, who is German, told me that this what they call chanterelles in Germany. 😱

That’s a little tip if you are traveling in Germany in the fall. Click here to jump to my Germany travel page to find out more.

Eat Local, Eat Seasonal

I try really hard to utilize only local fresh produce, not only because it’s healthier, cheaper and has less carbon footprint but because I believe in supporting my local farms.

There is a mushroom guy (James) at my local farmer’s market. He’s always there, year round.

fresh mushrooms
Click the image to check out Screaming Oaks Mushroom Farm

His mushrooms were something I used to skip over because I was afraid of them. I’m big on texture in food so mushrooms always seemed useless to me.

But there they were. Every week. And they were plentiful when other produce was scarce. I couldn’t ignore them anymore.

Wild mushrooms

Get Over The Fear. Find The Flavor.

So I challenged myself to find ways to not only use mushrooms, but to LOVE mushrooms.

Some of you are already there. You get it.

For those who don’t get it but want to try, I would suggest taking a nod from the French. They have mastered the art of making things that usually don’t taste good taste absolutely amazing by cooking them with onions in butter and white wine.

Asian recipes also make mushrooms magic with the simple addition of soy sauce.

Baby Bella Steps

Here are a few mushroom recipes to try next time you see an assortment of wild mushrooms at your local market.

First, I’m a big fan of buddha bowls. If you are too then you MUST check out Tish Wonder’s YouTube Channel. Her videos usually demo 3 different buddha bowl recipe ideas. These recipes are definitely for the foodie or the gourmet so if that is you, be prepared to fall in love and have a scratchpad nearby to scribble down the ideas.

Buddha Bowl from Tish Wonders

Tish often adds shitakki mushrooms to her bowls. This is where I learned that just a quick saute in olive oil and a splash of tamari (or soy sauce) turns the fairly neutral mushroom into a side dish star. Check out this video link. All the recipes are amazing but the 3rd bowl features the tamari mushrooms on the bowl pictured above (with brown rice, cabbage and butternut squash drizzled in a tahini dressing).

I am also currently obsessed with Wil Yeung’s YouTube channel. I recently made a miso ramen noodle dish from his channel that was easy and delicious. Noodles, broccoli, mushrooms in a miso sake broth. Yum. Click the link above…he uses mushrooms in lots of his recipes.

Once Upon A Mushroom Frittata

Today I decided to return to my roots and share a mushroom frittata recipe. Mushrooms actually go really well with eggs.

There are lots of mushroom frittata recipes online and they are all pretty similar.

The variations involve whether to just saute the onions or actually caramelize them, and which cheese to use (swiss or Gruyere).

I decided to kick it up a notch. As with most of my test kitchen experiments, I went through the fridge. Fresh bundle of thyme? Check. Quarter bottle of white wine? Check plus!

wild mushrooms

Once the onions were caramelized, I added more butter to the pan. Mushrooms in. Wine in. Fresh thyme. Then I get a facial because I’ve gotta put my nose right over the pan to take that aroma in!

Finished it with swiss and Gruyere cheese. It was soooooo good.

mushroom frittata
Caramelized Onion, Mushroom & Thyme Frittata

For your Easter Brunch, serve the mushroom frittata with a fancy salad and maybe some of those adorable mini-pumpernickel toasts. And 2 bottles of white wine. Enjoy!

I decided to do a little avocado toast on the side for lunch today. Smash up one ripe avocado with salt, crushed pepper, a good squeeze of lime juice and a little drizzle of olive oil. I had a whole grain pumpernickel bread for the toast and some fresh pea shoots for garnish. YUM!!

You can definitely make the frittata the day before and just warm it back up on low heat in the oven.

If you like this recipe, check out the entire frittata recipe collection!

Subscribe here so you don’t miss any recipes…I’m going to be in the kitchen all weekend. Mushroom lovers please comment with your favorite mushroom recipe.

Follow Frittata

Caramelized Onion and Mushroom Frittata

The glorious combination of butter, onions, mushrooms, thyme and white wine in a Sunday brunch frittata.
Prep Time: 25 minutes
Cook Time: 20 minutes
Total Time: 45 minutes
Course: Breakfast, brunch
Cuisine: American, French
Keyword: frittata, mushrooms, thyme, white wine
Servings: 8
Calories: 240kcal


  • 1 tbsp extra virgin olive oil
  • 2 tbsp butter
  • 1 small yellow onion, cut in half and sliced
  • salt and pepper
  • 2 cups assorted chopped fresh mushrooms
  • 1 tsp fresh thyme
  • 1/4 cup white wine
  • 8 eggs
  • 2/3 cup heavy cream
  • 1 tbsp Dijon mustard
  • 1/4 tsp baking powder
  • 1/2 cup swiss cheese, shredded
  • 3/4 cup Gruyere cheese, shredded


  • Preheat oven to 350°.
  • Heat an oven-safe medium non-stick saute pan over medium-low heat for 1 minute. Add 1 tbsp olive oil and 1 tbsp of the butter. Once melted add sliced onion, stir and season generously with salt and pepper. Leave alone for 7-10 minutes. Once the onions start to caramelize, stir them around to ensure even browning, about 15 minutes total.
  • Meanwhile, whisk together eggs, cream, Dijon and baking powder. Season with salt and pepper and set aside.
  • Raise heat to medium and add 1 tbsp butter to pan. Allow to melt and add the mushrooms. Stir to coat and combine with the onions. Continue to cool for about 4 minutes until mushrooms are beginning to soften but are still al dente.
  • Raise the heat to medium high. Wait 1 minute and then add white wine. Allow to simmer down until most of the liquid has evaporated, about 3 minutes. Add the fresh thyme (save a pinch for finishing). Get a good whiff of the pan now….mmmmmm.
  • Reduce heat to medium and pour egg mixture over the mushrooms. Stir gently to ensure everything is evenly distributed. Top with swiss and gruyere cheese, shimming the pan to allow the cheese to sink. Finish with the remaining pinch of fresh thyme and allow to cook on the stove for about 4 minutes until edges are set.
  • Transfer to oven and bake at 350° for 20 minutes or until set. Allow to rest 10 minutes before slicing and serving.


There is nothing better than the aroma of onions, mushrooms and fresh thyme cooking in butter and white wine.
This fancy frittata is perfect for Easter Sunday brunch.  Serve with a fancy green salad on the side.
Check out my other frittata recipes here:


Serving: 1slice | Calories: 240kcal | Carbohydrates: 6g | Protein: 13g | Fat: 18g | Saturated Fat: 9g | Trans Fat: 1g | Cholesterol: 204mg | Sodium: 167mg | Potassium: 288mg | Fiber: 2g | Sugar: 2g | Vitamin A: 667IU | Vitamin C: 2mg | Calcium: 232mg | Iron: 1mg
Tried this recipe?Let us know how it was!

Published by Jenny G

I'm sipping coffee in the morning, reading a cookbook for fun. Always planning my next trip and what I'll eat when I get there. Hoping to inspire others who share my love of cooking and eating, and to celebrate the wonderous diversity of food. I love to explore the world so I'll share my best itineraries and travel tips. Of course, sometimes I'd rather be snuggled up with a glass of wine and a good book so let's discuss those here too. And don't forget to feed the birds!

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