A French Onion Soup Grilled Cheese Sandwich is essentially French onion soup in grilled cheese form. Slices of sourdough is topped with gruyere cheese and wine, garlic and thyme infused caramelized onions and griddled to golden perfection.

Friday was the kind of day that calls for a cozy fire in the fireplace, a hot bowl of soup, grilled cheese sandwiches. 

French Onion Soup Grilled Cheese Sandwich to be exact.

I’m pretty sure after the first bite we collectively died and got a sneak peak at what heaven is like. And since that first glorious bite I’ve now decided that in my heaven, grilled cheese is served all the time. Like we’re talking breakfast, lunch and dinner here. With salt and vinegar chips. And pickles. And cake.

Onions are caramelized in butter with garlic, fresh thyme and combined with white wine before topping sourdough bread, gruyere cheese and griddled to golden perfection. 

French Onion Soup Grilled Cheese Sandwich ingredients.

To Make This French Onion Soup Grilled Cheese Sandwich You Will Need:

  • unsalted butter
  • yellow onions
  • thyme
  • salt
  • freshly ground black pepper
  • garlic
  • white wine
  • sourdough bread
  • gruyere cheese
  • salted butter

caramelized onions in a dutch oven.

First things first, caramelize the onions.

Melt 4 tablespoons of unsalted butter in a large pan over medium-high heat. Meanwhile, slice the top and the bottoms off of your yellow onions and slice them 1/4 of an inch thick. Keeping the onions uniformed in thickness will help them cook evenly.

When the butter has melted, add in the onions, 2 cloves minced garlic, 1 teaspoon thyme leaves, 3/4 teaspoon kosher salt and 1/2 teaspoon freshly ground black pepper. Toss well to combine and so the onions are coated in butter. Cover and cook undisturbed for 5 minutes.

After the 5 minutes, remove the lid and reduce the heat to medium-low. Cook for 40 minutes, stirring every 5 minutes until the onions are soft and a deep golden in color. Reduce the heat if you notice the onions are browning too soon. 

For a more thorough how-to click here for step-by-step instructions.

pouring in white wine.

Once the onions are soft and reach a deep golden color pour in 3 tablespoons of dry white wine. I use Sauvignon Blanc, however beer or beef broth can be substituted.

jammy caramelized onions.

After adding the wine, immediately scrape up any bits that are stuck to the bottom of the pan.

jammy caramelized onions.

The onions will be all jammy like so just pull the pan off of the burner so they don’t burn.

slice of sourdough with shredded gruyere.

Lay your slices of sourdough down and top with some of the grated gruyere. How much is up to you and the size of your slice of sourdough.

Topping gruyere with caramelized onions.

Top with a little of the caramelized onions.

looking down onto caramelized onion and gruyere topped sourdough.

Again, the amount is up to you. These slices are pretty large, however typically, this recipe should yield 4 maybe even 6 sandwiches.

top onions with more gruyere.

Top the onions with a little more of the smoked Gruyere.

oh baby.

butter sizzling on a hot griddle.

Preheat your griddle to 250° melt 1 tablespoon of butter per sandwich, spreading it around in pools roughly the size of your sandwiches.

griddling sandwiches.

Place the sandwiches down and increase the temperature of your griddle to 300°.

place sandwich into melted butter.

Gently pressing the sandwich into the butter.

Griddle the sandwiches until the underside is crisp and a deep golden brown.

add more butter to griddle before flipping sandwich.

Before flipping, use a spatula to lift the sandwich, melt another tablespoon of butter the same way you did before, and carefully flip the sandiwch on the second side. Gently pressing the sandwich into the butter.

golden brown grilled cheese on griddle.

Continue to cook until the second side deeply golden and crispy.

Cut your French Onion Soup Grilled Cheese Sandwich in half and serve immediately.

This is a pretty decadent grilled cheese. So fancy. And cheesy. It is exactly what I pictured the ultimate French onion soup grilled cheese to be.

Enjoy! And if you give this French Onion Soup Grilled Cheese Sandwich recipe a try, let me know! Snap a photo and tag me on twitter or instagram!

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Yield: 4 sandwiches

French Onion Soup Grilled Cheese Sandwiches

A French Onion Soup Grilled Cheese Sandwich is essentially French onion soup in grilled cheese form. Slices of sourdough is topped with gruyere cheese and wine, garlic and thyme infused caramelized onions and griddled to golden perfection.

Ingredients

  • 4 tablespoons unsalted butter
  • 2 large yellow onions, sliced 1/4-inch thick
  • 2 cloves garlic, finely minced
  • 1 teaspoon fresh thyme leaves
  • 3/4 teaspoon kosher salt
  • 1/2 teaspoon black pepper
  • 3 tablespoon dry white wine, beef stock or beer can be substituted
  • 8 slices sourdough bread
  • 8 ounces gruyere cheese, or regular gruyere will do
  • 4 tablespoons salted butter

Instructions 

  • Melt 4 tablespoons of butter in a large pan over medium-high heat.
  • Meanwhile, cut the top and the bottoms off of your yellow onions and slice 1/4 of an inch thick. Keeping the onions uniformed in thickness will help them cook evenly.
  • When the butter has melted, add in the onions, garlic, thyme, kosher salt and pepper. Toss until coated in the butter. Cover and cook undisturbed for 5 minutes.
  • After the 5 minutes, uncover and cook on medium-low heat for 40 minutes, stirring every 5 minutes until the onions are soft and a deep golden in color.
  • Pour in the wine and scrape any bits that accumulate on the bottom of the pot and then remove the pot off of the heat.
  • Build your sandwiches by topping the sourdough slices with grated gruyere, caramelizd onions and more gruyere. Lastly, place the second slice of bread on top.
  • Preheat your griddle to 250° melt 1 tablespoon of butter per sandwich, spreading it around in pools roughly the size of your sandwiches.
  • Place the sandwiches down and increase the temperature of your griddle to 300°. Gently pressing the sandwich into the butter.
  • Griddle the sandwiches until the underside is crisp and a deep golden brown.
  • Before flipping, use a spatula to lift the sandwich, melt another tablespoon of butter on the griddle (as you did before) and carefully flip the sandiwch on the second side. Gently pressing the sandwich into the butter.
  • Once the cheese is melted and the second side is crisp and golden, transfer to a cutting board and slice the sandwiches in half and serve.
Serving: 1g, Calories: 847kcal, Carbohydrates: 81g, Protein: 33g, Fat: 43g, Saturated Fat: 26g, Polyunsaturated Fat: 3g, Monounsaturated Fat: 12g, Trans Fat: 1g, Cholesterol: 123mg, Sodium: 1389mg, Potassium: 346mg, Fiber: 5g, Sugar: 7g, Vitamin A: 1264IU, Vitamin C: 7mg, Calcium: 661mg, Iron: 5mg