French Onion Grilled Cheese
French Onion Grilled Cheese
Ingredients
For the Caramelized Onions
- 2 pounds white onion, thinly sliced
- 1 pound red onion, thinly sliced
- 3 tablespoons unsalted butter
- 1 tablespoon olive oil
- 1 tablespoon sherry vinegar
- 1 teaspoon kosher salt
- 1/2 teaspoon black pepper, freshly ground
- 4 sprigs fresh thyme
- 1 bay leaf
- 1/2 cup beef broth
- 1 teaspoon balsamic vinegar
For the Grilled Cheese
- 8 slices sourdough bread
- 1 1/2 cups low-moisture mozzarella cheese, shredded
- 1 1/2 cups Gruyère cheese, shredded
- 1/4 cup mayonnaise
- 4 tablespoons unsalted butter
Instructions
- 1
Prepare the onions: Thinly slice both white and red onions. Set aside.
⏱️ 10 min
- 2
Caramelize the onions in an Instant Pot: Set your Instant Pot to the 'Sauté' function. Add 3 tablespoons of unsalted butter and 1 tablespoon of olive oil to the pot. Once melted, add the sliced onions and sauté until they have softened, about 8-10 minutes, stirring occasionally.
⏱️ 10 min
- 3
Pressure cook the onions: Stir in the sherry vinegar, kosher salt, black pepper, fresh thyme sprigs, and bay leaf. Secure the lid on the Instant Pot, set the vent to 'Sealing', and pressure cook on 'High' for 15 minutes.
⏱️ 15 min
- 4
Finish the caramelized onions: Once the pressure cooking cycle is complete, allow for a 5-minute natural release, then carefully quick release any remaining pressure. Remove the lid. Switch the Instant Pot back to 'Sauté' mode. Add the beef broth to deglaze the pot, scraping up any browned bits from the bottom. Continue to sauté and reduce the liquid until the onions are deeply caramelized and most of the liquid has evaporated, about 8-10 minutes. Stir in the balsamic vinegar and remove the thyme sprigs and bay leaf. Set the caramelized onions aside.
⏱️ 15 min
- 5
Assemble the sandwiches: For each sandwich, place one slice of sourdough bread on a clean surface. Layer 1/4 cup of shredded mozzarella cheese on top of the bread. Spoon a generous amount (about 1/4 cup) of the prepared caramelized onions over the mozzarella. Add another 1/4 cup layer of shredded Gruyère cheese. Spread mayonnaise evenly on one side of a second slice of sourdough bread. Place this mayonnaise-coated bread slice on top of the sandwich, with the mayo-side facing up.
⏱️ 10 min
- 6
Grill the sandwiches: Melt 1 tablespoon of unsalted butter in a large skillet or griddle over medium heat. Carefully place one or two assembled sandwiches into the pan, mayo-side down first. Cook for 4-6 minutes, or until the bread is golden brown and crispy. Flip the sandwich and cook on the other side for another 4-6 minutes, or until the second side is golden brown and the cheese is thoroughly melted and gooey. Repeat with remaining sandwiches, adding more butter to the pan as needed.
⏱️ 20 min•🌡️ 325
- 7
Serve: Remove the grilled cheese from the pan, cut it in half, and serve immediately.
⏱️ 5 min
Kitchen Tools
Nutrition Facts (per serving)
French Onion Grilled Cheese
Ingredients
For the Caramelized Onions
- 2 pounds white onion, thinly sliced
- 1 pound red onion, thinly sliced
- 3 tablespoons unsalted butter
- 1 tablespoon olive oil
- 1 tablespoon sherry vinegar
- 1 teaspoon kosher salt
- 1/2 teaspoon black pepper, freshly ground
- 4 sprigs fresh thyme
- 1 bay leaf
- 1/2 cup beef broth
- 1 teaspoon balsamic vinegar
For the Grilled Cheese
- 8 slices sourdough bread
- 1 1/2 cups low-moisture mozzarella cheese, shredded
- 1 1/2 cups Gruyère cheese, shredded
- 1/4 cup mayonnaise
- 4 tablespoons unsalted butter
Instructions
- 1
Prepare the onions: Thinly slice both white and red onions. Set aside.
⏱️ 10 min - 2
Caramelize the onions in an Instant Pot: Set your Instant Pot to the 'Sauté' function. Add 3 tablespoons of unsalted butter and 1 tablespoon of olive oil to the pot. Once melted, add the sliced onions and sauté until they have softened, about 8-10 minutes, stirring occasionally.
⏱️ 10 min - 3
Pressure cook the onions: Stir in the sherry vinegar, kosher salt, black pepper, fresh thyme sprigs, and bay leaf. Secure the lid on the Instant Pot, set the vent to 'Sealing', and pressure cook on 'High' for 15 minutes.
⏱️ 15 min - 4
Finish the caramelized onions: Once the pressure cooking cycle is complete, allow for a 5-minute natural release, then carefully quick release any remaining pressure. Remove the lid. Switch the Instant Pot back to 'Sauté' mode. Add the beef broth to deglaze the pot, scraping up any browned bits from the bottom. Continue to sauté and reduce the liquid until the onions are deeply caramelized and most of the liquid has evaporated, about 8-10 minutes. Stir in the balsamic vinegar and remove the thyme sprigs and bay leaf. Set the caramelized onions aside.
⏱️ 15 min - 5
Assemble the sandwiches: For each sandwich, place one slice of sourdough bread on a clean surface. Layer 1/4 cup of shredded mozzarella cheese on top of the bread. Spoon a generous amount (about 1/4 cup) of the prepared caramelized onions over the mozzarella. Add another 1/4 cup layer of shredded Gruyère cheese. Spread mayonnaise evenly on one side of a second slice of sourdough bread. Place this mayonnaise-coated bread slice on top of the sandwich, with the mayo-side facing up.
⏱️ 10 min - 6
Grill the sandwiches: Melt 1 tablespoon of unsalted butter in a large skillet or griddle over medium heat. Carefully place one or two assembled sandwiches into the pan, mayo-side down first. Cook for 4-6 minutes, or until the bread is golden brown and crispy. Flip the sandwich and cook on the other side for another 4-6 minutes, or until the second side is golden brown and the cheese is thoroughly melted and gooey. Repeat with remaining sandwiches, adding more butter to the pan as needed.
⏱️ 20 min•🌡️ 325 - 7
Serve: Remove the grilled cheese from the pan, cut it in half, and serve immediately.
⏱️ 5 min