Take lunch to the next level with this Caramelized Onion Grilled Cheese! It has all the melty goodness of your favorite grilled cheese sandwich combined with the flavor of sweet-savory caramelized onions! It’s an easy meal packed with deliciousness that everyone in your family will love.
In this Caramelized Onion Grilled Cheese, the classic comfort meal gets a kick of major flavor with perfectly golden caramelized onions, plenty of cheese and crusty bread!
If you love a good grilled cheese sandwich and can’t imagine them being any more wonderful, get ready for an upgrade you never knew you needed! Once you add golden brown, slow-cooked caramelized onions and plenty of gouda cheese or gruyere cheese to your sandwich, you’re never going to want another type of grilled cheese sandwich again!
This Caramelized Onion Grilled Cheese is absolutely irresistible and a cozy, comforting meal you won’t want to miss!
Ingredients needed
Like any homemade sandwich, feel free to use your favorite bread and cheese to make this caramelized onion grilled cheese recipe fit your taste preferences. Here’s a note on the ingredients we like to use:
- Yellow onions: The best type of onions to caramelize for a balanced sweet-savory flavor.
- Salted butter: For sautéing the onions and providing them with richness.
- Olive oil: To sauté the onions.
- Kosher salt and black pepper: To enhance the flavors.
- White wine vinegar: Helps to deglaze the pan and adds complex flavor.
- Cheese: Use your favorite cheese! We especially love the combination of Gouda, Gruyère, or cheddar cheese with the onions.
- Bread: Crusty slices of bread cut to about ½ inch thick work best for grilled cheeses.
How to make this recipe
It does require a bit of time to caramelize the onions, but with one bite of this sandwich, you’ll see it was totally worth it! Here’s how everything comes together:
- Caramelize onions: Add the onions, 2 tablespoons butter, and olive oil to a large skillet over medium heat. Season with salt and pepper, to taste. Allow the onion to cook and reduce for 30-35 minutes, stirring every 5-7 minutes, until the onions have achieved a rich deep golden brown color.
- Mix cheese with cooked onion: Once the onions are golden brown, add the vinegar to the pan to deglaze and stir for another 1-2 minutes or until the vinegar has evaporated. Remove onions from the pan using a slotted spoon (use the same pan to toast bread). Taste for salt and adjust to taste. Combine cheese and onion in a small bowl and set aside.
- Toast and assemble: Slather both sides of each piece of bread with the butter. Heat the same pan you cooked the onions in over medium low heat. Place slices of bread in the skillet (as many as can fit) and lightly toast for 1 minute to warm it through and create a light crust. Flip each slice of bread, then pile on onion/cheese mixture.
- Serve: Place the other slice of bread on top, with the hot toasted side in contact with the cheese. Cook for 2-3 minutes per side, pressing down gently with a spatula, until the bread is golden and crispy and the cheese is fully melted. Transfer to a cutting board and cut in half. Serve immediately.
Expert tips
- Cutting the onions: We recommend thinly slicing the onions, so they maintain their structure but are cut thinly enough that they caramelize nicely. It’s best to cut them all the same thickness, so they cook at the same rate.
- Heat level: For perfectly deep golden brown caramelized onions it’s best to cook them low and slow. This will ensure they have the best flavor and have a silky texture.
- Cooking the onions: Stir the onions frequently as they’re caramelizing, you don’t want them to burn. If they do start to burn, turn the heat down a bit and continue to stir. You can also add a teaspoon or two of water to help prevent burning, if they start getting a little too dark too quickly.
- Bread options: Be sure the bread isn’t too thick where the cheese doesn’t melt or too thin where the bread won’t hold. My favorite is sourdough or Tuscan Pane from Trader Joe’s. Ciabatta bread, or French bread will also work!
- Cheese: Freshly shredded cheese will melt better and taste more delicious than pre-shredded cheese. However, you can use pre-shredded or cheese slices, if preferred.
Frequently asked questions
What cheese goes with caramelized onion?
Gouda, Gruyère, or cheddar cheese are my personal favorites but you can honestly use your favorite cheese of choice. Provolone and Swiss cheese are other options that pair nicely with caramelized onions. You can even combine 2-3 different cheeses for a more complex flavor.
What is the secret to a good grilled cheese sandwich?
Slather the slices of bread with plenty of butter, then slowly and gently toast it over medium-low heat. Allow it to cook on the hot pan at least 1 minute before flipping. Your sandwich will be evenly golden brown, with a crisp exterior and a wonderfully cheesy center.
What goes good with grilled cheese sandwich?
Storing leftovers
We recommend eating your grilled cheese sandwiches as soon as you’ve made them for the best flavor and texture, but they can be stored in the fridge for 24 hours.
- In the refrigerator: Store grilled cheese in an airtight container for up to 24 hours.
- Reheating: To keep it nice and crispy, you can reheat your sandwich in a skillet over medium heat until warmed through, or in the air fryer for 2-3 minutes at 350 degrees F.
More delicious sandwich recipes
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Caramelize Onions: Add the onions, 2 tablespoons butter, and olive oil to a large skillet over medium heat. Season with salt and pepper, to taste. Allow the onion to cook and reduce for 30-35 minutes, stirring every 5-7 minutes, until the onions have achieved a rich deep golden brown color.
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Once the onions are golden brown, add the vinegar to the pan to deglaze and stir for another 1-2 minutes or until the vinegar has evaporated. Remove onions from the pan using a slotted spoon (use the same pan to toast bread). Taste for salt and adjust to taste. Combine cheese and onion in a small bowl and set aside.
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Toast: Slather both sides of each piece of bread with the butter. Heat the same pan you cooked the onions in over medium low heat. Place slices of bread in the skillet (as many as can fit) and lightly toast for 1 minute to warm it through and create a light crust. Flip each slice of bread, then pile on onion/cheese mixture.
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Place the other slice of bread on top, with the hot toasted side in contact with the cheese. Cook for 2-3 minutes per side, pressing down gently with a spatula, until the bread is golden and crispy and the cheese is fully melted. Transfer to a cutting board and cut in half. Serve immediately.
- Bread Options: You’ll want to use bread that is cut to about ½ inch thick. You don’t want it too thick where the cheese doesn’t melt or too thin where the bread won’t hold. My favorite is sourdough or Tuscan Pane from Trader Joe’s. Ciabatta bread, or French bread will also work!
- Cheese: Gouda, Gruyère, or cheddar cheese are my personal favorites but you can honestly use your favorite cheese of choice. I sometimes like to combine 2-3 different cheeses. Shredded cheese works best for melting but cheese slices will also work.
Serving: 1sandwich, Calories: 568kcal, Carbohydrates: 35g, Protein: 21g, Fat: 39g, Saturated Fat: 22g, Polyunsaturated Fat: 2g, Monounsaturated Fat: 12g, Trans Fat: 1g, Cholesterol: 110mg, Sodium: 868mg, Potassium: 264mg, Fiber: 4g, Sugar: 8g, Vitamin A: 847IU, Vitamin C: 6mg, Calcium: 489mg, Iron: 2mg
Nutrition information is automatically calculated, so should only be used as an approximation.
Recipe by: Layla Atik // Gimme Delicious | Photography by: Eat Love Eats
