Pin A decadent twist on classic grilled cheese, this sandwich combines caramelized onions with gooey melted cheese for a deeply savory, next-level comfort food experience.
Ingredients
- For the Caramelized Onions: 2 tablespoons unsalted butter
- For the Caramelized Onions: 2 large yellow onions, thinly sliced
- For the Caramelized Onions: 1 teaspoon sugar
- For the Caramelized Onions: 1/2 teaspoon salt
- For the Caramelized Onions: 1/4 teaspoon freshly ground black pepper
- For the Caramelized Onions: 1 teaspoon fresh thyme leaves (or 1/2 teaspoon dried)
- For the Caramelized Onions: 1 tablespoon balsamic vinegar
- For the Sandwich: 4 slices sourdough or country style bread
- For the Sandwich: 2 tablespoons unsalted butter, softened
- For the Sandwich: 1 cup (about 100 g) shredded Gruyère cheese
- For the Sandwich: 1 cup (about 100 g) shredded mozzarella cheese
- For the Sandwich: 2 teaspoons Dijon mustard
Instructions
- Step 1:
- Melt 2 tablespoons butter in a large skillet over medium heat. Add sliced onions, sugar, salt, and pepper. Cook, stirring occasionally, until onions are golden brown and deeply caramelized, about 25–30 minutes.
- Step 2:
- Stir in thyme and balsamic vinegar cook another 2 minutes until fragrant. Remove from heat and set aside.
- Step 3:
- Butter one side of each bread slice. Spread Dijon mustard on the unbuttered side of two slices.
- Step 4:
- Layer half the Gruyère and mozzarella onto the mustard side. Top with a generous spoonful of caramelized onions, then the remaining cheese. Place the other bread slices on top, buttered side facing out.
- Step 5:
- Heat a clean skillet or griddle over medium low heat. Cook sandwiches 3–5 minutes per side, pressing gently and flipping once, until bread is golden and cheese is fully melted.
- Step 6:
- Let rest 1 minute before slicing. Serve hot.
Pin 
Pin Pairs beautifully with tomato soup or a simple green salad.