Description
These Grilled Steak Sandwiches are a perfect blend of juicy flat iron steak, caramelized Vidalia onions, creamy triple cream brie, and a tangy horseradish sauce. Finished with fresh arugula and crisp radishes on grilled bread, this sandwich makes a flavorful and satisfying meal ideal for lunch or dinner.
Ingredients
Horseradish Sauce
- 1/2 cup mayonnaise
- 1 tablespoon prepared horseradish
- 2 teaspoons Dijon mustard
- 2 teaspoons Worcestershire sauce
- 2 tablespoons minced chives
- 1/2 teaspoon lemon zest
- 2 tablespoons lemon juice
- 1/2 teaspoon freshly cracked black pepper
- Salt, to taste
Steak and Toppings
- 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, to taste
- Freshly cracked pepper, to taste
Bread
- Sandwich bread, such as rustic or sourdough, 12 slices (for 6 sandwiches)
Instructions
- Caramelize Onions: In a skillet, melt the butter over medium heat. Add the thinly sliced Vidalia onions and toss to coat them thoroughly in the butter. Season with salt and freshly cracked black pepper. Cook the onions, stirring occasionally, until they turn a deep golden brown color, indicating caramelization is complete. Set aside once done.
- Prepare Horseradish Sauce: In a bowl, whisk together the mayonnaise, prepared horseradish, Dijon mustard, Worcestershire sauce, minced chives, lemon zest, lemon juice, freshly cracked black pepper, and salt until smooth and fully combined. Refrigerate the sauce until ready to assemble the sandwiches.
- Season Steak: About 30 minutes before cooking, season the flat iron steak generously with salt and pepper. Let it rest at room temperature to ensure even cooking.
- Grill the Steak: Preheat a grill or grill pan over medium-high heat. Place the steak on the grill and cook for 4-5 minutes per side for medium doneness on thicker cuts, or 3-4 minutes per side for thinner steaks. Adjust cooking time longer if you prefer medium-well or well-done. Once cooked, transfer the steak to a plate and loosely tent with foil to rest.
- Slice Steak: After the steak has rested for about 5 minutes, thinly slice it against the grain. Optionally, season the slices lightly with flaky sea salt to enhance flavor.
- Grill Bread and Assemble: Grill the sandwich bread, cut side down, on the grill or grill pan for 1-2 minutes until lightly toasted. Spread the prepared horseradish sauce on both sides of the bread slices. Layer the bottom slices with caramelized onions, sliced steak, creamy brie slices, arugula, and thinly sliced radishes. Top with the other slice of bread and serve immediately while warm.
Notes
- Flat iron steak is ideal for its tenderness and flavor, but you can substitute with flank or skirt steak if preferred.
- Caramelizing onions requires patience; cooking them low and slow will yield the best sweetness and depth of flavor.
- If you prefer extra heat, add a dash of hot sauce to the horseradish sauce.
- For a dairy-free version, omit the brie or substitute with a vegan cheese alternative.
- Serve these sandwiches with a side of chips or a fresh salad for a complete meal.
