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grilled steak sandwiches
Main Course, Sandwiches

Grilled Steak Sandwiches

These grilled steak sandwiches are perfect for summer! They're loaded with tender grilled steak, creamy brie, caramelized onions, horseradish sauce, arugula, and radishes. This sandwich is perfect for a picnic or a summer bbq!
Prep Time: 20 mins
Cook Time: 30 mins
Total Time: 50 mins
Makes: 4 sandwiches


Horseradish Sauce

  • 1/2 cup mayonnaise
  • 1 tablespoon prepared horseradish
  • 2 teaspoons dijon mustard
  • 2 teaspoons Worcestershire saue
  • 2 tablespoons minced chives
  • 1/2 teaspoon lemon zest
  • 2 tablespoons lemon juice
  • 1/2 teaspoon freshly cracked black pepper
  • salt, to taste

Steak Sandwiches

  • 1 1/2 lbs flat iron steak
  • 2 tablespoons salted butter
  • 2 sweet vidalia onions, thinly sliced
  • 10 oz triple cream brie, sliced
  • 3 cups arugula
  • 6 radishes, sliced
  • kosher salt
  • freshly cracked pepper


  • In a skillet, melt the butter and add the sliced onions. Toss the onions well in the butter and season with salt and pepper. Cook, stirring occasionally, until the onions are deeply golden brown and then set aside.
  • Whisk all the horseradish sauce ingredients together until smooth and refrigerate until ready to use.
  • About 30 minutes before you plan to cook, season the steaks with salt and pepper and let them sit at room temperature.
  • Preheat a grill or grill pan over medium-high heat. For medium temperature, grill the steak for 4-5 minutes per side for thicker steaks, 3-4 minutes for thinner steaks. Cook longer for medium-well or well-done steaks. Transfer to a plate and tent with foil.
  • After the steak has rested, thinly slice it and lightly season with flaky sea salt if desired.
  • Grill the bread, cut side down, for 1-2 minutes. Assemble the sandwiches by spreading the horseradish sauce on both sides. Add the caramelized onions, sliced steak, brie slices, and top with arugula and radishes. Top with the other slice of bread and serve immediately.