This French Onion Grilled Cheese levels up your grilled cheese game with sweet and savory caramelized onions and gooey, melty cheese all tucked between crispy, golden slices of bread. This sandwich is comfort food at its finest – perfect for lunch, dinner or a cozy snack!
Looking for more tasty sandwich recipes? Make sure to try my Slow Cooker Italian Beef Sandwiches and Crispy Chicken Sandwich or whip up a quick sammie with our favorite Egg Salad or Chicken Salad!
French Onion Grilled Cheese Recipe
Grilled cheese is already a family favorite in our house, but when you add the rich, savory flavor of caramelized onions? It is a whole new level of delicious! This French Onion Grilled Cheese is everything you love about classic French Onion soup, wrapped up in a golden, crispy sandwich.
This decadent and indulgent French Onion Soup Grilled Cheese is quick enough for a busy weekday lunch but feels fancy enough to impress at the dinner table. There is just something magical about the combination of caramelized onions and melty cheese, isn’t there?
Whether you are serving this tasty sandwich for a quick lunch with the kids or a laid-back dinner for the family, it’s sure to be a hit. Plus, I have all the tips to make it easy and foolproof – because let’s face it, who does not love a golden, gooey grilled cheese?
Why You’ll Love This Recipe
Say hello to your new favorite sandwich! This French Onion Grilled Cheese combines the sweet, savory flavor of caramelized onions with the melty goodness of Gruyère and Provolone. A simple recipe that’s as family-friendly as it is indulgent!
- Rich Flavor: The caramelized onions bring a deep, savory sweetness that pairs perfectly with the creamy, nutty Gruyère and mild Provolone. Combined with crispy, golden toasted bread, this sandwich is loaded with amazing flavor.
- Easy to Make: Simple ingredients and straightforward steps mean this recipe is approachable even for beginners. The onions take a bit of time to caramelize but that’s a great time to prep the other ingredients.
- Family-Friendly: Kids and adults alike will adore the combination of flavors and textures. Consider swapping in a more kid-friendly cheese if yours aren’t fans of Gruyere.
Ingredients Needed
This easy recipe combines sweet caramelized onions with gooey Gruyère and provolone, grilled to perfection on crispy bread. A family-friendly meal ready in under an hour. Let’s take a quick look at what you’ll need for this recipe and, as always, you can find the full printable recipe in the recipe card at the end of this post.
For The Caramelized Onions
- Butter and Extra Virgin Olive Oil: This is what the onions will cook in slowly until caramelized. I like to use a little oil with the butter to keep the butter from browning too quickly but all butter or all olive oil can be used.
- White and Yellow Onions: A mix of both adds complexity to the flavor.
- Worcestershire Sauce: Enhances the savory, umami notes.
- Spicy Mustard: Adds a subtle tangy kick.
- Italian Seasoning & Garlic Powder: Infuse the onions with aromatic depth.
- Granulated Sugar: Optional, but it helps the onions caramelize more evenly.
- Salt & Pepper: Balances and enhances the overall flavor.
For The Sandwich
- Gruyère and Provolone Cheeses: A perfect pairing of nutty and creamy flavors that melt beautifully.
- Bread: Choose sturdy slices like sourdough or French bread for the best results.
- Mayonnaise: Optional, but it adds a crisp, golden finish to the bread when grilled. Don’t like mayo? Swap in butter instead.
How to Make French Onion Grilled Cheese
Imagine biting into a perfectly crispy, grilled cheese sandwich bursting with the rich, savory flavor of caramelized onions and the gooey, melty goodness of Gruyère and Provolone cheeses. That’s exactly what you get with this French Onion Grilled Cheese!
Combining the classic comfort of a grilled cheese with the sophisticated flavor of French onion soup, this sandwich is sure to be a hit. This recipe is surprisingly simple to make and comes together quickly. Let’s take a quick look at how to make this caramelized onion grilled cheese and, as always, you can find the full printable recipe in the recipe card at the end of this post.
Caramelize the Onions
- Peel and thinly slice the onions.
- Heat butter and extra virgin olive oil in a large skillet over medium heat.
- Add the sliced onions to the skillet.
- Mix in Worcestershire sauce, mustard, Italian seasoning, garlic powder, sugar (if using), salt, and pepper.
- Cook, stirring occasionally, until the onions are deeply golden and caramelized.
Assemble the Sandwich
- Spread mayonnaise on one side of each bread slice (optional, for extra crispiness) and place in clean skillet.
- Layer a slice or two of provolone on each slice of bread.
- Top with caramelized onions.
- Place a few slices of Gruyere on top.
- Finally, top with another slice of bread (mayo-side out).
Grill the Sandwich
- Cook for 2–3 minutes per side until the bread is golden brown and the cheese is melted.
- Slice in half and serve immediately with your favorite chips or soup.
Storage and Make-Ahead Information
This sandwich is best made and served immediately. That being said, here are some options for making ahead and storing leftovers:
- Make Ahead: Caramelized onions can be prepared up to 3 days in advance and stored in the refrigerator.
- Freezing: Assemble the sandwiches without grilling, wrap them tightly, and freeze for up to 2 months. Thaw before grilling.
- Reheating: Warm leftovers in a skillet or oven to retain crispness.
Frequently Asked Questions
Any bread will work. Sourdough, French bread, or even brioche are great choices for this recipe.
Adding a pinch of sugar helps the caramelization of the onions. It’s an optional ingredient.
You can use butter or skip it entirely, though mayonnaise helps achieve a golden, crispy crust.
Sure can! Caramelized onions store well in the refrigerator for up to 5 days or in the freezer for up to 3 months. Reheat them gently in a skillet before using them in your grilled cheese.
Absolutely! Gruyère is classic for French onion flavors, but you can also use Swiss, mozzarella, provolone, or even sharp cheddar for a twist. Mixing cheeses can create a unique flavor and texture.
Cook on medium heat and consider covering the pan with a lid for a minute or two to trap heat and encourage melting.
Feel free to customize with extras like fresh thyme, a layer of Dijon mustard, crispy bacon, or even a slice of tomato for added flavor.
Variations to Try
- Considering upping the protein on this French Onion Grilled Cheese Sandwich by adding in your favorite deli meat – think roast beef, ham, or turkey!
- Gruyere and provolone are delicious but you’ll also love Swiss, Fontina, or Havarti for a different flavor profile.
- Add sautéed mushrooms or roasted red peppers for added depth of flavor and nurtition.
Trish’s Tips
- Caramelizing onions takes time so do not rush the process by turning up the heat. Low and slow cooking ensures the natural sugars develop their deep, sweet flavor.
- Stir the onions frequently but not constantly to prevent burning – this allows them to brown evenly.
- If you notice browned bits on the bottom of the pan, deglaze with a splash of broth, wine, or even water to incorporate those flavorful bits into the onions.
- For quicker melting, cut the cheese into thin slices or consider shredding the cheese instead of using slices.
- Gruyère is the classic choice for French onion flavors due to its creamy melt and nutty taste but can be substituted with Swiss cheese or your favorite cheese. Provolone cheese complements the flavor of Gruyere wonderfully.
- Spreading mayonnaise or softened butter on the outside of the bread ensures a crispy, golden crust.
- Cooking on medium heat prevents the bread from burning before the cheese melts.
- Gently press the sandwich with a spatula for better contact with the pan, ensuring even
browning and melting.
More Cheesy Recipes To Try
- Mac and Cheese
- Ham and Cheese Sliders
- Goat Cheese Stuffed Chicken Breast
- Chicken Cordon Bleu Soup
- Lazy Day Lasagna
French Onion Grilled Cheese
Ingredients
- 2 tablespoons salted butter
- 1 tablespoon extra virgin olive oil or salted butter
- 2 large white onions thinly sliced
- 2 large yellow onions thinly sliced
- 2 tablespoons Worcestershire sauce
- 2 teaspoons spicy brown mustard
- 1 teaspoon Italian seasoning
- ½ teaspoon garlic powder
- 1 teaspoon granulated sugar helps with the caramelization, optional
- ½ teaspoon fresh ground black pepper
- ½ teaspoon fine sea salt
- 6 slices bread French, sourdough, brioche, etc.
- 3 tablespoons mayonnaise optional, for spreading onto the bread
- 6 slices Provolone cheese
- 6 slices Gruyere cheese
Instructions
- Heat butter and extra virgin olive oil in a large skillet over medium heat.2 tablespoons salted butter, 1 tablespoon extra virgin olive oil
- Add the sliced onions, Worcestershire sauce, spicy brown mustard, Italian seasoning, garlic powder, sugar (if using), black pepper and salt. Stir to combine.2 large white onions, 2 large yellow onions, 2 tablespoons Worcestershire sauce, 2 teaspoons spicy brown mustard, 1 teaspoon Italian seasoning, ½ teaspoon garlic powder, 1 teaspoon granulated sugar, ½ teaspoon fine sea salt, ½ teaspoon fresh ground black pepper
- Cook, stirring occasionally, until the onions are golden brown and caramelized (about 20–25 minutes). Cook until the liquid evaporates. Set aside.
- Heat a clean skillet over medium heat.
- Spread mayonnaise on one side of each bread slice (optional, for extra crispiness).6 slices bread, 3 tablespoons mayonnaise
- Place bread in skillet, mayonnaise side down.
- Top with slices of Provolone, followed by the caramelized onions and finish with Gruyère.6 slices Provolone cheese, 6 slices Gruyere cheese
- Top with another slice of bread (mayo side facing out).
- Cook until the bread is golden brown and crispy, and the cheese is melted, about 2-3 minutes per side.
- Slice in half and serve immediately with your favorite chips.
Notes
- Make Ahead: Caramelized onions can be prepared up to 3 days in advance and stored in the refrigerator.
- Freezing: Assemble the sandwiches without grilling, wrap them tightly, and freeze for up to 2 months. Thaw before grilling.
- Reheating: Warm leftovers in a skillet or oven to retain crispness.
Caramelizing onions takes time so do not rush the process by turning up the heat. Low and slow cooking ensures the natural sugars develop their deep, sweet flavor.
Please see post above for more information, recipe tips and frequently asked questions.
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