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.
Servings: 4 sandwiches
Ingredients
Caramelized Onions
- 2 tablespoons Unsalted 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 Unsalted 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
