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gooey cheese, crusty bread, and incredible caramelized onions make my favorite version of this classic comfort food! caramleized onion grilled cheese | a flavor journal food blog

caramelized onion, havarti + mozzarella grilled cheese

sara a.
gooey cheese, savory onions, and crispy bread make my favorite version of this classic comfort food.  this is a small batch recipe for two people.  
5 from 1 vote
Prep Time 5 mins
Cook Time 10 mins
Total Time 15 mins
Course Main Course
Cuisine American
Servings 2 people


for caramelized onions : (or see the link in the notes for a step-by-step guide!)

  • 1 yellow onion
  • 1 Tbsp. unsalted butter
  • 1 Tbsp. olive oil
  • 1/2 tsp. fine sea salt

for grilled cheese sandwiches :

  • 4 1/4" thick slices crusty baked bread
  • 1/4 cup unsalted butter
  • 1/4 cup caramelized onions
  • 4 ounces havarti cheese
  • 4 ounces fresh mozzarella cheese


for caramelized onion :

  • Discard the ends and outside layer of the onion, then cut the onion in half.  Lay the cut sides down onto the cutting board, and slice both halves as thinly as possible.  Paper thin "half rings" are ideal.
  • In a large sauté pan over medium heat, melt 1 Tbsp. of unsalted butter and 1 Tbsp. of olive oil.  Once the butter is melted and foamy, scatter the thinly sliced onion into the pan.  Grind some fine sea salt on top of the onion, and toss to coat all of the onion slices with butter and salt.  
  • Allow the onion to cook and reduce for 30-40 minutes, stirring occasionally, (about every ten minutes), to develop an even layer of caramelization.  Once the onions have achieved a rich, deep golden / brown color, remove them with a slotted spoon, and set aside.

for grilled cheese sandwiches :

  • Spread one tablespoon of butter on one side of each slice of bread.  In the same pan you used to cook the onions, lay two slices of bread, butter side down, into the pan.
  • Top each slice immediately with two ounces of havarti, two tablespoons of caramelized onion, and then two ounces of mozzarella, to evenly divide the cheese and onions between the two sandwiches.
  • Top each cheese and onion pile with the remaining slices of bread, butter side up.  Cover the pan with a lid, and allow to cook for 2-3 minutes, or until the bottom slice of bread is browned in the pan.  Carefully flip the sandwiches over, careful to not spill any cheese out of the sides.
  • Cook the top slice of bread, now butter side down in the pan, for 3-4 minutes.  Cheese should be melted and gooey, and bread should be dark brown.
  • Remove the sandwiches from the pan, and transfer to a cutting board to rest for about one minute.  Once cool enough to touch, slice each in half and serve immediately.  Tomato soup works wonders with this sandwich. :) 
Keyword caramelized onion grilled cheese, fancy grilled cheese, havarti grilled cheese
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