Go Back
–+ servings
A perfectly grilled cheese sandwich cut in half, with melted cheese oozing out, showcasing caramelized onions.

Caramelized Onion Grilled Cheese

This recipe offers a delicious twist on the classic grilled cheese, featuring sweet caramelized onions and a blend of melty cheeses. It's perfect for a quick and satisfying meal that can be prepped ahead for busy families.
Print Recipe Pin Recipe
Prep Time 15 minutes
Cook Time 15 minutes
Onion Caramelizing 10 minutes
Total Time 40 minutes
Servings: 4 sandwiches
Course: Dinner, Lunch
Cuisine: American
Ingredients Equipment Method Notes

Ingredients
  

For the Caramelized Onions
  • 2 large yellow onions diced
  • 1 tsp fresh thyme minced
  • 1 tsp fresh rosemary minced
  • 1 tsp brown sugar
  • 1 tsp olive oil
  • 1.5 Tbsp butter
  • Salt and pepper to taste
For the Grilled Cheese
  • 8 slices good quality bread thick cut Artisan bread recommended
  • Mayonnaise for spreading
  • 12 oz Gruyere cheese sliced thinly or grated, at room temperature
  • 6 oz White cheddar cheese sliced thinly or grated, at room temperature
  • 4 slices Muenster cheese thin, at room temperature
  • 1.5 Tbsp butter divided
  • 1 tsp fresh rosemary minced

Equipment

  • Skillet
  • Plate

Method
 

  1. Heat 1 1/2 Tbsp butter and olive oil in a skillet over medium-low heat. Add diced onions, salt, pepper, fresh thyme, and 1 tsp of fresh rosemary. Sauté, stirring often, until onions are soft and starting to brown, about 10 minutes.
  2. Stir brown sugar into the onions and cook for another minute.
  3. Transfer the caramelized onions to a plate.
  4. Spread a thin layer of mayonnaise on one side of two pieces of bread.
  5. To the same skillet, add the remaining butter and rosemary. Heat over medium heat, swirling to coat the bottom of the skillet with the melted butter.
  6. Add both pieces of bread, mayonnaise side down, and cook until the bread is golden brown and crunchy, about 2-3 minutes.
  7. As soon as you add the bread to the skillet, add cheese to the top of each piece. Once the cheese begins to melt slightly, sprinkle a couple tablespoons of the caramelized onions over the top of one of the pieces of bread.
  8. When the bread is golden brown, sandwich the pieces of bread together and cook on low heat until the cheese is fully melted.
  9. Transfer the sandwich to a plate. Repeat with the remaining slices of bread and ingredients.
  10. Slice and enjoy!

Notes

This recipe is great for meal prep. You can caramelize the onions ahead of time and store them in the refrigerator. Assemble the sandwiches just before cooking for the best results.

Tried this recipe?

Let us know how it was!