A Caramelized Onion Grilled Cheese Sandwich is always tasty, but add in some fried mushrooms and lunch has been brought to another level. Golden mushrooms and sweet caramelized onions are sandwiched in between two slices of bread with melty swiss cheese. This is a tasty sandwich recipe that you will want to enjoy often!
This grilled cheese sandwich is perfect for lunch or dinner and excellent with a bowl of soup on a chilly day, or a side of chips and garlic dill pickles.
Celebrating Grilled Cheese Month
April is National Grilled Cheese Month. For me, that is a big thing, because we love grilled cheese! I will be sharing a few new sandwiches throughout the month that we have been enjoying and are in love with, including this Mushroom Caramelized Onion Grilled Cheese Sandwich.
Grilled Cheese Sandwiches are our go to when we are ready for lunch, but weren't prepared. I always keep caramelized onions in the fridge and the mushrooms are easy to fry up quickly.
Ingredients Needed For Caramelized Onion Grilled Cheese
A nice firm bread. I used a Rosemary Tuscan Pane bread that I bought from the grocery store bakery. I like how the rosemary bread pairs so well with the caramelized onion grilled cheese.
Caramelized Onions, these are super easy to make and this post tells you how to make caramelized onions in a quick and easy way!
Fried Mushrooms, I like to make this Sautéed Mushrooms with Umami.
Swiss Cheese, I like to buy the brick cheese and shred it for grilled cheese sandwiches. I find the cheese melts easier and faster when it is shredded.
Softened butter for coating the grilling side of the bread. I prefer to use salted butter but unsalted is fine as well.
Grill Pan, I love to use this grill pan to get the grill marks on my sandwich. I also like to use a wide spatula to flip the sandwich.
Box shredder to shred the swiss cheese.
Tips and Substitutions For The Best Grilled Cheese Sandwich
- Make sure the bread you use is a good sturdy bread. I like to use the Tuscan Pane bread. It holds up well to any sandwich I have grilled. Any artisan bread that is nice and firm will work.
- When turning the caramelized onion grilled cheese sandwich over to toast on the opposite side, be sure to use a wide thin spatula and use your other hand to help support the sandwich so it turns over without spilling the fillings out.
- Use a small cast iron skillet to press the sandwich down some while it is cooking. The sandwich will look super tall, and you want the cheese to melt and bring the sandwich together.
- Substitute the swiss cheese for one of your favorite cheeses. Good cheeses to use would be brie, pepper jack, mozzarella, monterey jack, and a smoked jack cheese is excellent also!
- Amp the sandwich up a little and add some protein to it. Ham or Bacon are good choices. My son likes to add pepperoni slices to his.
- Substitute fried baby portobello mushrooms in place of the crimini.
- Toast the inside of the sandwich before assembling it to grill, this will make it extra crispy and buttery.
- Sprinkle some red pepper flakes into the caramelized onions when cooking to add a little bit of heat.
Other Sandwich Recipes To Try
Grilled Cheese Sandwich with Bacon, Jalapeno, and Rhubarb Sauce
Grilled Ham and Blue Cheese Sandwich
Shrimp and Avocado Chaffle Sandwich
Slow Cooker BBQ Beef Brisket Sandwich
Slow Cooker Pulled Pork Sandwiches
Steak Sandwich with Blue Cheese Spread
*If you made this Caramelized Onion Grilled Cheese Sandwich with Mushrooms, please give it a star rating*
📖 Recipe
Caramelized Onion Grilled Cheese With Mushrooms
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Ingredients
- 1 fried mushrooms recipe
- ½ tablespoon olive oil
- 1 teaspoon umami seasoning (or salt and pepper to taste)
- 8 slices tuscan pane bread
- 2 cups shredded swiss cheese
- 1 cup caramelized onions
- ½ tablespoon thyme leaves
- 2 tablespoon butter softened
Instructions
- Cook the mushrooms as directed in the linked recipe.
- Lay out 4 slices of the bread on a cutting board. Coat one side of each slice of bread with the butter.
- Top each slice with ¼ cup of swiss cheese. Place ¼ of the caramelized onions, mushrooms, and fresh thyme on top of the cheese. Top the mushrooms with the remaining cheese and bread.
- Heat a large grill pan over medium-low heat. Add the sandwiches, working in batches, and cook for 5 minutes per side, or until fully toasted and golden brown.
Video
Notes
Tips and Substitutions For The Best Grilled Cheese Sandwich
- Make sure the bread you use is a good sturdy bread. I like to use the Tuscan Pane bread. It holds up well to any sandwich I have grilled. Any artisan bread that is nice and firm will work.
- When turning the caramelized onion grilled cheese sandwich over to toast on the opposite side, be sure to use a wide thin spatula and use your other hand to help support the sandwich so it turns over without spilling the fillings out.
- Use a small cast iron skillet to press the sandwich down some while it is cooking. The sandwich will look super tall, and you want the cheese to melt and bring the sandwich together.
- Substitute the swiss cheese for one of your favorite cheeses. Good cheeses to use would be brie, pepper jack, mozzarella, monterey jack, and a smoked jack cheese is excellent also!
- Amp the sandwich up a little and add some protein to it. Ham or Bacon are good choices. My son likes to add pepperoni slices to his.
- Substitute fried baby portobello mushrooms in place of the crimini.
- Toast the inside of the sandwich before assembling it to grill, this will make it extra crispy and buttery.
- Sprinkle some red pepper flakes into the caramelized onions when cooking to add a little bit of heat.
Sara says
Link for mushrooms is broken; can you help?
Shelby Law Ruttan says
Hi Sara, I fixed the link in the recipe card. Thank you for letting me know. Shelby