Steak Sandwich

Ingredients

For the Steak Sandwich:

• 1 (8-ounce) flank steak
• 1 teaspoon salt
• 1 teaspoon ground black pepper
• 1 tablespoon Worcestershire sauce
• 1 tablespoon olive oil
• 1 tablespoon butter
• 1 large onion, sliced into rings
• 2 small ciabatta rolls
• 2 slices aged cheddar cheese
• 1/2 cup baby arugula

For the Horseradish Mayo:

• 1/2 cup mayonnaise
• 1 tablespoon prepared horseradish
• 1/2 clove garlic, minced
• 2 tablespoons sour cream
• Olive oil, for brushing
• Steps to Make It
• Prepare the Steak
• Gather the ingredients.
• Pound the flank steak to tenderize. Season it all over with salt, pepper, and Worcestershire sauce. Cover and let marinate for at least 30 minutes, or up to 4 hours.
• In a large skillet, heat the oil over medium-high heat. Once the oil is hot, add the steak. Cook for 3 minutes, without moving, then flip and cook for an additional 3 minutes for a rare to medium-rare steak. If you like it more well done, you can cook it longer. Remove the steak from the heat and set aside. Tent with foil to keep warm.
• Add butter to the same pan and melt over medium-low heat. Add the onions and sauté for 20 minutes or until the onions are softened and starting to caramelize.
• While the onions cook, prepare the horseradish mayo.
• Prepare the Horseradish Mayo and Assemble
• Preheat the broiler to high. Whisk together the mayonnaise, horseradish, garlic, and sour cream.
• Brush the rolls with oil and toast directly on the oven rack under the broiler or in a pan until golden brown. Watch closely as the bread can burn easily.
• Slice the steak against the grain.
• Slather the horseradish mayo over the cut sides of each roll. Divide steak between the rolls, then add the cheese, half of the onions, and arugula. Serve immediately and enjoy.