French Dip Steak Sandwich with Horseradish Mayo
Juicy, marinated flank steak, seared to perfection, served on warm French rolls with caramelized onions and a zesty horseradish mayo. Dip it in a rich, savory beef jus for the ultimate indulgence! A labor of love, but totally worth it.
Ingredients
- For the Steak Marinade:
- ⅓ cup soy sauce
- 3 tablespoons olive oil
- 3 tablespoons Worcestershire sauce
- 2 tablespoons balsamic vinegar
- 1 tablespoon honey
- 2 cloves garlic smashed
- For the Sandwich:
- 1½ – 2 pounds flank steak
- Fresh cracked black pepper
- Olive oil or vegetable oil
- 1 large onion peeled and thinly sliced
- 1 tablespoon unsalted butter
- Salt and pepper to taste
- 4 6-inch French or hoagie rolls, sliced in half
- For the Jus:
- 2 cups beef stock
- ¼ teaspoon garlic powder
- ¼ teaspoon onion powder
- ¼ teaspoon dried thyme
- 1 tablespoon Worcestershire sauce
- For the Horseradish Mayo:
- ¾ cup Duke’s mayonnaise
- 2 –3 tablespoons prepared horseradish to taste
- 1 tablespoon finely chopped chives optional
- 1 tablespoon Dijon mustard
- 2 teaspoons lemon juice
- Salt and pepper to taste
Instructions
- Marinate the Steak:
- In a large zip-top bag, combine all marinade ingredients and mix well.
- Add the steak, seal, and massage the marinade into the meat.
- Marinate for at least 30 minutes at room temperature or up to 6 hours in the fridge.
- Prepare the Jus:
- In a small saucepan, combine beef stock, garlic powder, onion powder, thyme, and Worcestershire sauce.
- Set aside; warm later when serving.
- Make the Horseradish Mayo:
- Whisk together mayonnaise, horseradish, chives, Dijon mustard, and lemon juice.
- Season with salt and pepper to taste.
- Refrigerate until ready to use.
- Cook the Steak:
- Remove the steak from the marinade and pat dry.
- Generously season with fresh cracked black pepper.
- Heat a cast iron skillet over medium-high heat and add olive oil.
- Sear the steak for about 5 minutes per side for medium-rare.
- Remove from heat, tent with foil, and let rest for at least 15 minutes.
- Caramelize the Onions:
- In the same skillet, reduce heat to medium-low.
- Add butter and onions, sauté for 6-8 minutes, stirring occasionally, until softened and caramelized.
- Season with salt and pepper.
- Slice the Steak:
- Thinly slice the steak against the grain at a 45-degree angle.
- Warm the Jus:
- Heat the prepared jus over low heat.
- Assemble the Sandwiches:
- Optional: Lightly toast the rolls under a broiler for a warm, soft texture.
- Spread horseradish mayo on the top half of each roll.
- Add caramelized onions to the bottom half.
- Top with sliced steak and season with a pinch of salt and pepper.
- Press the sandwich together and slice diagonally.
- Serve warm with a side of jus for dipping.
Notes
- Make-Ahead: The marinade and mayo can be prepped a day in advance.
- Serving Suggestion: Pair with crispy fries or a light salad for a complete meal.