Caramelized Onion, Mushroom & Swiss Panino

Caramelized Onion, Mushroom & Swiss PaninoCaramelized Onion, Mushroom & Swiss Panino

In the week after Christmas but before the New Year, I’m a little cooked out. I have to admit, making elaborate meals just isn’t on my radar. I do however need to eat and want something quick and delicious. My go to? PANINI!

They’re perfect for lunch and if you add a salad (gah did I just mention salad in two posts back to back, feel my head quick ; 0 ) or a hearty bowl of SOUP and you’re all set.

Caramelized Onion, Mushroom & Swiss Panino

Panini can be filled with just about anything your heart desires. The key to me is the bread, it needs to be crusty on the outside yet soft on the inside. A panini press is also a big help but isn’t a deal breaker if you don’t have one. An old school cast iron pan works wonders.

I whipped up this delicious caramelized onion, sauteed baby bella, swiss panino pictured above for The Mushroom Channel. I can  honestly say I’ve made this for the past three days in a row and am not tired of it yet!

Caramelized Onion, Mushroom & Swiss Panino
Photo Credit: Angie, Eclectic Recipes

To keep you panini happy also check out this Portabello Mushroom and Basil pesto Panini pictured above from Angie of Eclectic Recipes.


Caramelized Onion, Mushroom & Swiss Panino

Total Time 0:00


  • 2 tablespoons extra virgin olive oil
  • 1 medium red onion – thinly sliced
  • kosher salt/ black pepper
  • 1 tablespoon sugar
  • 2 tablespoons unsalted herb butter
  • 1 tablespoon extra virgin olive oil
  • 6 ounces baby bella mushrooms – sliced
  • 4 slices Pan Bigio – sliced thick on the bias
  • 4 slices Swiss cheese
  • 4 cherry tomatoes – halved, optional


Place 2 tablespoons olive oil into a sauté pan over medium-low heat. Add onions. Season with salt/pepper. Cook until onions are softened. Add sugar, continue cooking, stirring as necessary until onions have caramelized (approximately 30 minutes). Set aside.

Into a small sauté pan add: 2 tablespoons herb butter and 1 tablespoon olive oil. Heat over medium heat. Add mushrooms. Season with salt/pepper. Cook for approximately 4-5 minutes. Set aside.

Heat your Panini press to 350 degrees. Equally distribute mushrooms between two slices of bread. Equally top with mushrooms with caramelized onions. Place 2 slices of Swiss cheese on each piece of bread. (NOTE: if using tomatoes place them on at this time) Place corresponding slices of bread on top. Lightly brush tops of bread with room temperature herb butter.

Place sandwiches onto hot panini press. Cook for approximately 4-5 minutes until bread is toasted and cheese has melted.


Recipe Notes

If you do not have a panini grill, use a non-stick skillet and heat over medium-high heat. Place sandwich onto hot pan. Using a heavy pan (such as a cast iron pan), weigh sandwich down. Cook as directed above.

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  1. 1

    This is gorgeous, Paula! I love melted cheese between bread. Caramelized onions make this over-the-top amazing!

  2. 2

    that looks beyond simple and delicious! the best combination ever!

    when my brother was visiting, the only thing he requested I make from my blog were toasts topped with caramelized onions and smoked gouda that I then put under a broiler. We love our bread and cheese 😉

  3. 3

    Ahhhh this looks wonderful! I just purchased 5 onions to carmelize tonight….. yum!

  4. 4

    Just got a panini press for Christmas so I am loving all these panini recipes you linked!!

  5. 5

    Looks tasty Paula! I need to use my panini press more often! 🙂

  6. 6

    Onions and mushrooms are perfection to begin with, but then you add cheese? Ohhhh yum!

  7. 7

    Ohhh, glorified grilled cheese, you can’t go wrong. I used to think the flavorful aged cheeses were the secret, but after having my last one with carmelized onions, I’m thinking that might be the new secret. Thanks for sharing!

  8. 8

    That caramelized onion panini looks incredible! Wow!

  9. 9
    Tammie /

    I know I am probably missing it somehow but I have looked and looked for the caramelized onion, sauteed baby bella, swiss panino recipe but can not find it. I would LOVE to make this if I can find the recipe. Any help? 🙂

  10. 10

    I want one of these RIGHT NOW. Seriously! I love a good panini and can’t think of how to make one any better than with the combination of caramelized onions and mushrooms…okay, maybe a few thin shavings of truffle to make it really decadent? Hey, I can wish, right?


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