Perfect Steak Sandwich with Creamy Horseradish Sauce (Print version)

Juicy sliced steak, grilled onions, crisp greens, and a sharp creamy horseradish sauce tucked into toasted ciabatta.

# Ingredients:

For the steak

01 - 1 1/2 lb (680 g) skirt steak or flank steak, trimmed
02 - 2 tablespoons olive oil, plus more for the onions
03 - 2 garlic cloves, finely grated
04 - 1 teaspoon kosher salt
05 - 1/2 teaspoon black pepper
06 - 1 teaspoon smoked paprika
07 - 1/2 teaspoon dried oregano

For the creamy horseradish sauce

08 - 1/2 cup (120 g) mayonnaise
09 - 1/4 cup (60 g) sour cream
10 - 2-3 tablespoons prepared horseradish, drained if watery
11 - 1 teaspoon Dijon mustard
12 - 1 tablespoon fresh lemon juice
13 - 1 tablespoon finely chopped chives
14 - Pinch of kosher salt

For assembly

15 - 1 large red onion, sliced into 1/2-inch rounds
16 - 4 ciabatta rolls, split and toasted
17 - 2 cups baby arugula
18 - Optional: 4 slices provolone or Swiss cheese

# Instructions:

01 - Mix olive oil, garlic, salt, pepper, smoked paprika, and oregano. Rub over the steak and let it stand at room temperature for 20 minutes while you heat the grill or skillet.
02 - Stir mayonnaise, sour cream, horseradish, Dijon, lemon juice, chives, and salt until smooth. Refrigerate until ready to assemble.
03 - Brush onion slices lightly with oil. Grill or sear over medium-high heat for 3-4 minutes per side, until charred at the edges and tender. Set aside.
04 - Grill or sear the steak over medium-high heat for 3-4 minutes per side for medium-rare, depending on thickness. For USDA guidance, cook whole beef steaks to 145°F with a 3-minute rest.
05 - Transfer the steak to a board and rest for 5-10 minutes. Slice thinly against the grain so the sandwich eats tender.
06 - Spread creamy horseradish sauce on both cut sides of each toasted roll. Layer arugula, grilled onions, sliced steak, and cheese if using. Serve warm.

# Good to know:

01 - Best served right after assembling while the bread is crisp.
02 - Horseradish strength varies, so taste the sauce before adding the full amount.
03 - Leftover steak can be used if sliced thin and warmed gently.

Back