The Soup-Sandwich Combo of Your Dreams

Few combinations are as classic—or as comforting—as a warm bowl of soup and a sandwich grilled to perfection. Here we’ve combined the two with a recipe for French Onion Soup Grilled Cheese, a union that’s at once gooey, soupy, crunchy, and yes, incredibly cheesy. Gruyère and Fontina cheeses strike a harmonious chord with a sweet and savory onion compote, while a side of arugula delivers a healthy dose of bright green contrast.

Stir onions frequently to prevent them from burning.

To check if the pan is hot, carefully hover your hand a few inches away from the pan. When it’s hot, you’ll be able to feel the heat.

Rotate the bread slices in the pan so that they toast evenly throughout.

⅛ ounce thyme
2 yellow onions
1 lemon
1½ teaspoons butter
8 teaspoons mayonnaise, divided
4 slices sourdough bread
2 tablespoons flour
16 ounces vegetable stock
1½ teaspoons Dijon mustard
2 ounces shredded Fontina cheese
3 ounces shredded Gruyère cheese
5 ounces baby arugula

1 tablespoon olive oil
2 tablespoons water
kosher salt
black pepper
10″ medium pan
12″ large nonstick pan
aluminum foil


Prepare Ingredients:

Strip thyme leaves, discarding stems. Peel onions, halve, and thinly slice. Halve lemon. In a large bowl, whisk together juice of 1 lemon and 1 tablespoon olive oil to make dressing. Season with⅛ teaspoon salt and pepper as desired and set aside.

Cook Onions:

Heat butter in a medium pan over medium-high heat. When butter is foamy, add thyme and onions and cook, stirring occasionally, until light brown and softened, about 7 minutes (see Recipe Tip). Add 2 tablespoons water and reduce heat to medium. Cook, stirring continuously, until onions are golden brown and very soft, about 5 minutes more.

Toast Bread:

While onions cook, place bread slices on a clean dry surface. Spread 2 packets mayonnaise evenly over tops. Heat a large nonstick pan over medium-high heat (see Recipe Tip). Once pan is hot, add bread slices mayonnaise-side down and cook on one side until bottom is slightly toasted, 2-3 minutes. Remove bread from pan and set aside to cool, toasted-side up.

Simmer Onion Gravy:

Add flour to pan with onions over medium heat and stir vigorously until flour is no longer visible, 1 minute. Add vegetable stock. Increase heat to high, bring to a boil, then reduce heat to medium-high and simmer, stirring occasionally, until sauce is thickened and reduced by ¼, 4 minutes. Season with ¾ teaspoon salt and pepper as desired. Divide half of gravy between 2 bowls and cover with foil. Cook remaining gravy until reduced by half, 5 minutes more. Remove pan from heat.

Assemble Grilled Cheese:

Flip bread toasted-side down and spread remaining 2 packets mayonnaise evenly over tops. Flip bread and spread mustard evenly over toasted side. Divide half of cheese mix between 2 bread slices. Spoon onion gravy from pan over cheese, dividing evenly. Top with remaining cheese mix and remaining bread slices mustard-side down.

Cook Grilled Cheese:

Return nonstick pan from bread to medium heat. Once pan is hot, add sandwiches and cook until bread is golden and cheese is melted, about 4 minutes per side. Divide grilled cheeses between 2 plates, cut in half, and serve with French onion soup. Add arugula to bowl with lemon oil dressing, toss to coat, and serve with soup and sandwiches.

Love experimenting in the kitchen? Try Plated!

Get 25% off your first four weeks of Plated!

On the List?

Subscribe to Plated's Newsletter

Thanks for signing up!

There was an error signing you up.
Please check that your email is valid. Try again