Caramelized Onion Grilled Cheese
Updated Jan 08, 2026
This post may contain affiliate links. Please read our disclosure policy.
This Caramelized Onion Grilled Cheese is a French onion soup–inspired twist on the classic comfort sandwich. It’s layered with deeply caramelized onions, melty cheddar gruyere cheese, and a swipe of fig butter, then grilled until golden with a crisp parmesan crust on the outside.
Looking for the perfect soup to dip this grilled cheese in? Try my Easy Tomato Soup or Creamy Tuscan Chicken Orzo Soup.
🐝 Quick Look: Caramelized Onion Grilled Cheese Recipe
- ⏱ Prep Time: 15 minutes
- 🔥 Cook Time: 1 hour 10 minutes
- ⏳ Total Time: 1 hour 25 minutes
- 🍽 Servings: 4 sandwiches
- ⚡ Calories: ~524 per sandwich
- 🍳 Cook Method: Stovetop caramelization, pan-fried grilled cheese
- 🧂 Main Ingredients: Onions, cheddar gruyere cheese, bread
- 👩🍳 Flavor Profile: Savory, rich, deeply caramelized, cheesy
- ⭐ Difficulty: Easy to moderate. Mostly hands-off onion caramelization with quick stovetop assembly
SUMMARIZE & SAVE THIS CONTENT ON
Why You’ll Love This Recipe
- French onion soup–inspired comfort food with deeply caramelized onions and melty cheese in every bite. Try my One Pot French Onion Pasta for a similar flavor.
- Simple ingredients, big payoff using pantry staples like bread, butter, onions, and cheese.
- Optional fig butter adds balance with a subtle touch of sweetness that pairs perfectly with savory onions. Use the rest of the fig butter to make Boursin and Fig Phyllo Cups.
- Crispy parmesan crust is optional but worth it for extra crunch.
- Perfect for dipping into Easy Tomato Soup or serving alongside your favorite soup.
Table of Contents
Key Ingredients
See the recipe card below for the complete list of ingredients with exact quantities.
- Fig Spread: Optional, but highly recommended. Use any fig spread you like, including fig butter from Trader Joe’s. The subtle sweetness pairs perfectly with the caramelized onions and balances the richness and saltiness of the cheese.
- Sherry: Used to deglaze the pan after the onions caramelize, sherry adds depth and enhances the savory, French onion soup–style flavor. You can substitute white wine, beef broth, or even a splash of balsamic vinegar if needed.
Tips and Substitutions
- Bread: Use a sturdy, bakery-style bread that can hold up to the filling. Sourdough, Tuscan pane, or a rustic country loaf work best and crisp nicely without getting soggy.
- Cheese: I usually use a mix of cheddar and gruyère, but you can use all cheddar or all gruyère depending on what you have. Just make sure it’s freshly grated for the best melt.
- Fig Butter: Optional, but highly recommended. It adds a subtle sweetness that pairs beautifully with the caramelized onions. Any fig spread works, including fig butter.
- Sherry Substitute: If you don’t have sherry, you can deglaze the pan with white wine, beef broth, or even a splash of balsamic vinegar.
- Parmesan Crust: Totally optional. Skipping it still gives you a great grilled cheese, but adding parmesan to the pan creates an extra-crispy, restaurant-style finish.
- Make Ahead: Caramelized onions can be made up to 5 days in advance and stored in the fridge, making assembly quick and easy. I love making a big batch to use throughout the week. Try swapping them in for the shallots in my Caramelized Shallot Dip or add as a topping to a Fall Harvest Bowl.
How to Make Caramelized Onion Grilled Cheese
See the recipe card below for full instructions and exact amounts.
- Add thinly sliced onions to a pot with butter and olive oil over medium heat. Season with salt and stir to coat.
- Reduce heat to medium-low and cook, stirring occasionally, until the onions are deeply golden and jammy. Deglaze the pan with sherry.
- Make the grilled cheeses. Melt butter then layer one piece of bread with caramelized onions.
- Next, add a layer of cheese. Optionally, spread fig spread on the other half of bread and place on top.
- Cook the sandwiches in butter over medium-low heat, flipping once, until the bread is golden and the cheese is melted.
- Sprinkle parmesan directly into the pan, place the sandwich on top, and cook briefly until a crispy crust forms. Flip and repeat if desired.
Caramelized Onion Grilled Cheese FAQs
What cheese goes best with caramelized onions in grilled cheese?
Gruyère and cheddar are both excellent choices. Gruyère melts smoothly and adds a nutty, savory flavor, while cheddar brings richness and sharpness. You can use one or a blend of both depending on what you have.
Can I make caramelized onion grilled cheese without fig jam or fig butter?
Yes. The fig butter is completely optional. It adds a subtle sweetness, but the grilled cheese is still delicious with just caramelized onions and cheese.
How long does it really take to caramelize onions?
Caramelizing onions properly takes time. Expect anywhere from 30-60 minutes or more over medium-low heat. Cooking them slowly is key to developing deep flavor without burning.
What type of bread works best for caramelized onion grilled cheese?
Use a sturdy, bakery-style bread that can hold up to the filling. Sourdough, Tuscan pane, or a rustic country loaf work best and crisp nicely in the pan.
Can I make this caramelized grilled cheese ahead of time?
The sandwiches are best fresh, but you can caramelize the onions up to 5 days in advance and store them in the refrigerator. Assemble and grill the sandwiches when ready to serve. I love making a big batch of caramelized onions to use in various dishes throughout the week. Swap them in for the shallots in Caramelized Shallot Dip or add as a topping to a Fall Harvest Bowl.
Soup Pairings
Caramelized Onion Grilled Cheese
Think French onion soup meets grilled cheese in this elevated comfort food classic. This sandwich is layered with deeply caramelized onions, melty cheddar gruyere cheese, and an optional swipe of fig butter for subtle sweetness. Finished with a crispy parmesan crust on the outside for extra crunch.
Equipment
- Large Pan
Ingredients
Caramelized Onions
- 2 tablespoons Butter
- 1 tablespoon Extra Virgin Olive Oil
- 2 large Yellow Onion, thinly sliced
- ¼ cup Sherry
- Kosher Salt & Black Pepper
Grilled Cheese
- 8 slices Bread, use a sturdy bread
- 1 cup White Cheddar Cheese, freshly grated
- 1 cup Gruyère Cheese, freshly grated
- ½ cup Parmesan Cheese, grated (optional)
- 4 tablespoons Fig Butter, optional
- 2 tablespoons Butter, divided per sandwich (more as needed)
Instructions
Caramelized Onions
- Start the onions: In a Dutch oven or large pan, melt the butter and olive oil over medium heat. Add the sliced onions and stir to coat. Cook for 5 minutes, then season with a generous pinch of salt.
- Caramelize: Reduce heat to medium low and cook for 30–60 minutes, stirring occasionally, until deeply caramelized and jammy. Cooking time will vary based on pan, heat, and onion quantity.
- Deglaze: Pour in the sherry to deglaze the pan, scraping up any browned bits. Season with salt and pepper to taste. Transfer onions to a bowl and set aside.
Grilled Cheese
- Assemble: Lay out two slices of bread per sandwich. Optionally spread fig butter on one slice. Top with caramelized onions and evenly sprinkle on the grated cheese. Add the second slice of bread on top.
- Toast: Heat a large nonstick pan over medium low heat and melt a small pat of butter. Add the sandwich and cook for 3–5 minutes until golden. Flip, add more butter if needed, and cook another 3–5 minutes until the cheese is melted.
- Parmesan crust (optional): Increase heat to medium high. Lift the sandwich and sprinkle parmesan cheese directly into the pan. Place the sandwich back onto the parmesan and cook for about 1 minute until a crust forms. Flip and repeat on the other side.
- Finish: Repeat with remaining sandwiches. Slice in half and serve warm.
Notes
- Bread choice: Use a sturdy, thick-cut bread that can hold up to the caramelized onions and melted cheese. Sourdough, Tuscan pane, or a rustic country loaf work well. Avoid soft sandwich bread, which can become soggy.
- Caramelizing onions: Low and slow is key. If the onions start to brown too quickly, reduce the heat. Cooking time will vary depending on pan size, heat level, and onion quantity.
- Sherry substitutes: If you do not have sherry, you can substitute with red or white wine, a splash of vinegar, or beef broth to deglaze the pan.
- Cheese choice: Use a cheddar gruyere blend or a mix of white cheddar and gruyère. Amounts are estimates; use enough cheese to fully cover the bread for even melting.
- Fig butter: Optional, but recommended for a subtle sweetness that balances the savory onions and cheese.
- Parmesan crust: The parmesan crust step is optional. It adds extra crunch and flavor, but the grilled cheese is still delicious without it.
- Heat control: Cook the sandwiches over medium low heat to ensure the bread toasts evenly and the cheese melts before browning too quickly.
Nutrition
Calories: 524kcal, Carbohydrates: 21g, Protein: 21g, Fat: 39g, Saturated Fat: 21g, Polyunsaturated Fat: 2g, Monounsaturated Fat: 12g, Trans Fat: 0.5g, Cholesterol: 106mg, Sodium: 737mg, Potassium: 208mg, Fiber: 1g, Sugar: 10g, Vitamin A: 1055IU, Vitamin C: 7mg, Calcium: 669mg, Iron: 0.5mg
Nutrition information is automatically calculated, so should only be used as an approximation.
Like this recipe? Rate and comment below!
My absolute favorite grilled cheese! The sweet caramelized onions pair perfectly with the fig butter. And don’t skip the crispy parmesan crust!
A soup’s best friend right here. I made a bunch of caramelized onions for another recipe of yours and used the leftovers to make this grilled cheese! Such a great idea!