Description
This French Onion Grilled Cheese sandwich combines richly caramelized onions with melted Gruyère and Swiss cheeses on buttery sourdough bread, creating a gourmet twist on a classic grilled cheese. The deep, sweet onions infused with thyme and a splash of beef broth add a savory depth to the sandwich, while the golden crust provides a satisfying crunch. Perfect as a comforting main course, this recipe is both easy to prepare and deliciously indulgent.
Ingredients
Scale
Caramelized Onions
- 2 tablespoons unsalted butter
- 1 large yellow onion, thinly sliced
- 1 teaspoon sugar
- 1/4 teaspoon salt
- 1/4 teaspoon black pepper
- 1 teaspoon fresh thyme leaves (or 1/4 teaspoon dried thyme)
- 1/4 cup beef broth
Sandwich
- 4 slices sourdough or French bread
- 4 slices Gruyère cheese
- 4 slices Swiss cheese
- 2 tablespoons mayonnaise (optional)
- Additional butter for grilling
Instructions
- Caramelize the Onions: In a skillet over medium heat, melt the butter and add the thinly sliced onions. Cook for about 5 minutes until they begin to soften, then stir in the sugar, salt, and black pepper. Continue cooking, stirring frequently, for 20–25 minutes until the onions become deeply caramelized and golden brown.
- Add Thyme and Broth: Stir in the fresh or dried thyme leaves, then pour in the beef broth. Cook for an additional 2–3 minutes, allowing the liquid to absorb completely. Remove the skillet from heat once the onions are richly flavored and the broth is absorbed.
- Assemble the Sandwiches: Take two slices of bread and layer one slice of Gruyère and one slice of Swiss cheese on each. Evenly divide the caramelized onions over the cheese layers, then add another slice of Gruyère and Swiss on top. Cap each with the remaining bread slices.
- Prepare for Grilling: Spread mayonnaise or softened butter on the outside surfaces of each sandwich slice to promote even browning and a crispy crust.
- Grill the Sandwiches: Heat a clean skillet over medium heat. Place the sandwiches in the skillet and grill for 3–4 minutes per side. Press gently with a spatula to ensure even contact and melting. Cook until the bread is golden brown and the cheese inside is melted.
- Serve Warm: Slice the sandwiches in half and serve immediately for the best taste and texture.
Notes
- For a vegetarian version, substitute vegetable broth for the beef broth.
- You can use all Gruyère or all Swiss cheese depending on your preference.
- Mayonnaise on the outside helps the bread brown evenly but can be replaced with butter.
