Description
This French Onion Grilled Cheese sandwich combines sweet, deeply caramelized onions with a melty blend of Gruyère and mozzarella cheeses on crisp, buttery sourdough bread. It offers a gourmet twist on the classic grilled cheese, perfect for a comforting lunch or dinner.
Ingredients
Onion Caramelization
- 2 tablespoons unsalted butter
- 1 large yellow onion, thinly sliced
- 1/4 teaspoon salt
- 1/2 teaspoon sugar
- 1/4 teaspoon black pepper
- 1/2 teaspoon fresh thyme leaves (or 1/4 teaspoon dried thyme)
- 1 tablespoon dry white wine or beef broth (optional)
Sandwich
- 4 slices sourdough or French bread
- 1 cup shredded Gruyère cheese
- 1/2 cup shredded mozzarella cheese
- 1 tablespoon mayonnaise or softened butter (for bread)
Instructions
- Caramelize the Onions: Melt 1 tablespoon of butter in a skillet over medium heat. Add the sliced onions along with salt, sugar, black pepper, and thyme. Cook slowly, stirring frequently, until the onions are deeply golden and caramelized, about 20–25 minutes. In the last few minutes, stir in white wine or beef broth if using, to deglaze the pan. Remove from heat and set aside.
- Prepare the Cheese Mixture: In a bowl, combine the shredded Gruyère and mozzarella cheeses, mixing them evenly.
- Butter the Bread: Spread mayonnaise or softened butter on one side of each bread slice to ensure a golden, crispy exterior when grilled.
- Assemble and Cook the Sandwich: Heat a clean skillet over medium heat. Place two slices of bread, buttered side down, on the pan. Top each with a generous portion of the cheese mixture, followed by half of the caramelized onions. Cover with the remaining bread slices, buttered side up.
- Grill Until Golden and Melty: Cook until the bottom slices are golden brown and the cheese begins to melt, approximately 3–4 minutes. Carefully flip the sandwiches and cook the other side until it is equally golden and the cheese is fully melted.
- Rest and Serve: Remove the sandwiches from the skillet, let them rest for 1–2 minutes to set, then slice and serve warm.
Notes
- You can substitute Swiss cheese for Gruyère if desired.
- For a stronger onion flavor, use red onions or add a splash of Worcestershire sauce during caramelization.
- This sandwich pairs wonderfully with tomato soup or a fresh green salad for a complete meal.
