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–+ servings
Close-up of a perfectly grilled cheese sandwich, cut in half, with melted cheese oozing out. This is a great grilled cheese recipe meal prep.

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.
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Prep Time 15 minutes
Cook Time 20 minutes
Caramelizing Onions 1 minute
Total Time 36 minutes
Servings: 4 sandwiches
Course: Dinner, Lunch
Cuisine: American
Ingredients Equipment Method Notes

Ingredients
  

For the Caramelized Onions
  • 2 yellow onions onions diced
  • 1 tsp fresh thyme minced
  • 1 tsp fresh rosemary minced
  • 1 tsp brown sugar
  • 1 tsp olive oil
  • 1.5 Tbsp butter
  • 1/2 tsp salt to taste
  • 1/4 tsp black pepper to taste
For the Grilled Cheese
  • 8 slices bread thick cut artisan bread recommended
  • 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 at room temperature
  • 1 Tbsp butter divided
  • 1 tsp fresh rosemary minced
  • 1 Tbsp mayonnaise for spreading

Equipment

  • Skillet
  • Spatula
  • 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 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 starts 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 to a plate. Repeat with the remaining slices of bread and ingredients.
  10. Slice and enjoy.

Notes

This recipe is a great base for meal prep. You can caramelize the onions ahead of time and store them in the refrigerator. Assemble the sandwiches just before cooking or cook them and reheat gently.

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