Go Back
Two halves of a steak grilled cheese stacked on parchment, toasted sourdough, sliced beef, melted Gruyere and caramelized onions, a bowl of French onion soup behind

Steak Grilled Cheese

Seared steak, jammy caramelized onions and Gruyère inside buttery toasted sourdough, all made in one skillet, with French onion soup on the side for dipping.
Print Recipe Pin Recipe
Prep Time 10 minutes
Cook Time 55 minutes
Total Time 1 hour 5 minutes
Servings: 2 sandwiches
Course: Dinner
Cuisine: American
Calories: 1300
Ingredients Method Notes

Ingredients
  

For the caramelized onions
  • 2 medium yellow onions thinly sliced
  • 2 tbsp butter
  • salt a pinch
  • 1 tsp Worcestershire sauce
  • 1/2 tsp fresh thyme leaves or a pinch of dried
For the steak
  • 1 ribeye or New York strip steak about 12 oz (340 g), 1 inch (2.5 cm) thick
  • salt and black pepper
  • 1 tbsp neutral oil high smoke point
For the sandwiches
  • 4 thick slices sourdough or a country loaf
  • 2 tbsp butter softened, or mayonnaise
  • 4 oz Gruyère 115 g, sliced or coarsely grated

Method
 

  1. Melt the butter in a skillet over medium heat. Add the onions and a pinch of salt and cook, stirring every few minutes, for 30 to 35 minutes until deep amber and jammy, adding a tablespoon of water to scrape up any browned bits. Stir in the Worcestershire and thyme for the last minute. Move to a bowl.
  2. Pat the steak dry and season well with salt and pepper. Wipe the skillet, heat over high heat until it just smokes, add the oil and sear the steak 4 to 5 minutes per side for medium-rare (about 130°F / 54°C). The USDA safe minimum for beef steaks is 145°F (63°C) with a 3-minute rest.
  3. Rest the steak 10 minutes, then slice it thinly against the grain.
  4. Butter one side of each bread slice. On two slices, butter side down, layer a quarter of the cheese, half the steak, half the onions and another quarter of the cheese. Top with the remaining bread, butter side up.
  5. Wipe the skillet and cook the sandwiches over medium-low heat 3 to 4 minutes until golden. Flip, cover with a lid and cook another 3 to 4 minutes until the cheese is melted. Rest 1 minute, cut in half and serve with French onion soup for dipping.

Notes

Make ahead: caramelize the onions up to several days ahead and refrigerate; warm them briefly before assembling.
Leftover steak: slice it cold, then let it sit 15 minutes at room temperature before building the sandwiches.
Cheese: provolone, Swiss (Emmental) or young white cheddar work too; half Gruyère and half provolone gives flavour and stretch.
Storage: best eaten right away. Leftover sandwiches can be refrigerated and reheated in a covered skillet over low heat, but the bread will be softer.
Nutrition is an estimate per sandwich calculated from standard ingredient values, not a laboratory analysis.