We’re making a classic french dip sandwich, even better with seared and sliced flank steak, caramelized onions, and spicy horseradish mayonnaise. This is a next-level at home sandwich. Fire up the cast iron – you can’t miss this!
A few weeks ago I took my friend Emily to my one of my most nostalgic Los Angeles sandwich spots, Philippe’s. If you’ve lived in Los Angeles for any amount of time, you know how iconic their French Dip sandwiches are. Philippe’s is so ingrained in my family that my grandfather used to take my dad there a handful of decades ago. We’ve spent more than a few special occasions there and it felt like a right of passage to introduce it to my friend Emily.
As she and I sat down with our sandwiches, with so much to catch up on, I thought to myself – wait, are these sandwiches actually good or are they just good because they’re so ingrained in my memory? The verdict? They’re old school and yes, in fact, good. –
BUT! If I were to make this sandwich at home (which, spoiler alert – I did) I’d turn up the volume. Layers. We need more. Think: buttery onions, steak instead of roast beef, and a spicy, spicy horseradish mayonnaise.
This is a dinner-quality sandwich and I need you in on this with me. You ready? Of course you are.
Here are the ingredients you’ll need for this french dip sandwich recipe:
• I like a 2 pound flank steak. Flank steak is a long, flat cut of beef with a good amount of grain that slices perfectly for sandwiches with just enough chew and beef flavor.
• marinade for the beef that includes: soy sauce, olive oil, Worcestershire sauce, balsamic vinegar, honey, and garlic
• onions, sliced for sautéing.
• spicy horseradish mayo that includes: Duke’s mayo (and Duke’s mayo only), prepared horseradish, chives, lemon, salt and pepper.
• au jus that includes: beef broth, onion powder, garlic powder, dried thyme and Worcestershire sauce.
• 6-inch french rolls or hoagie rolls
Start by marinating the steak in a savory, salty mixture of soy sauce, olive oil, and vinegar. The steak doesn’t have to marinante for long – 30 minutes or so will do – though if you have a few hours, longer is better.
Remove the steak from the marinade and bring it closer to room temperature before cooking. I leave the steak on the counter for 30 minutes. Just before searing in a hothothot cast iron, pat the steak dry with a paper towel. A dry steak will develop a nice crust in the hot pan rather than steaming the surface of the steak.
I cook the steak in a hot cast iron over medium high heat with olive oil for 5 minutes on each side. It’s very no fuss. If you’d like involve your oven, this reverse sear technique is the way to go.
As the steak marinates, cooks, and rests, there’s plenty of time to bring together the other stellar elements of this sandwich.
Horseradish mayonnaise MAKES this sandwich. It’s a saucy mixture of Duke’s mayonnaise, prepared horseradish, fresh chopped chives, a spoonful of dijon mustard, a squeeze of lemon juice, salt, and pepper. Add as much horseradish to the bowl as makes you happy. I like to add so much that it sometimes feels I’ve been punched in the nose but lol that’s just a personal preference.
No French Dip Sandwich would be complete without that dip dip.
Pour beef broth into a saucepan and heat gently with onion powder, garlic powder, and a few dried herbs. Add a bay leaf for extra credit.
I like to let the mixture simmer a bit to reduce and concentrate the flavors. It’s a simple dip – it really nicely soaks into the french rolls.
Melt thin sliced onions into butter to caramelize. Heap onto untoasted french rolls as the base. You could add provolone cheese or swiss cheese over the warm onions if you want even MORE.
Slice the steak against the grain to get the most tender bites and layer each sandwich with a heap of thin slices.
Spread generously with horseradish mayo and smoosh it onto the sandwich.
Be forewarned, if you make this you will absolutely be contracted to make it again and/or work it into the weekly dinner rotation. This sandwich is served best with an ice cold beer (in an ice cold glass) and hand cut fries if you’re feeling up to it. If you aren’t up to it Trader Joe’s frozen fries are delightfully crunchy cooked in the air fryer. Be obsessed with this sandwich with me! Enjoy!Print
For the steak marinade:
- 1/3 cup soy sauce
- 3 tablespoons olive oil
- 3 tablespoons Worcestershire sauce
- 2 tablespoons balsamic vinegar
- 1 tablespoon honey
- 2 smashed garlic cloves
For the sandwich:
- 1 1/2 – 2 pound 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
- 4 6-inch French or hoagie rolls, sliced in half horizontally
For the jus:
- 2 cups beef stock
- 1/4 teaspoon garlic powder
- 1/4 teaspoon onion powder
- 1/4 teaspoon dried thyme
- 1 tablespoon Worcestershire sauce
For the horseradish mayo:
- 3/4 cup Duke’s mayonnaise
- 2–3 tablespoons prepared horseradish (according to your taste)
- 1 tablespoon finely chopped chives (optional)
- 1 tablespoon Dijon mustard
- 2 teaspoons lemon juice
- Salt and pepper to taste
- This sandwich is a labor of love but wow it’s so worth it. Start by marinating the steak. Combine all of the marinade ingredients in a large zip-to-seal bag and massage to incorporate. Add the steak and allow to marinate for at least 30 minutes at room temperature. You can marinate the steak up to six hours in the refrigerator.
- While the steak marinates, make the jus by combining all of the ingredients in a small saucepan. You’ll heat the jus once the sandwich is assembled but it’s nice to be prepared.
- Make the horseradish mayo real quick by whisking together all of the ingredients in a small bowl. Taste and adjust seasoning to your preference.
- Once the steak has marinated, remove from the bag and pat dry with paper towels. Top generously with fresh cracked black pepper.
- Heat a cast iron skillet over medium-high heat until it’s really quite hot. Add a few glugs of olive oil. Sear steak, about 5 minutes per side, or until you think the steak is a lovely medium-rare. Remove from the pan to a cutting board and tent a piece of foil over the steak to let it rest for at least 15 minutes before slicing.
- Reduce the heat on the skillet to medium-low. Add butter and onions and sauté until tender and just beginning to caramelize, about 6-8 minutes. Season with salt and pepper.
- Once the steak has rested, use a sharp chef’s knife to slice it thinly against the grain at a 45 degree angle.
- Place the prepared jus over low heat to warm.
- To assemble the sandwiches, very lightly toast or rather, warm the sliced rolls on a baking sheet covered in foil under the broiler. This is optional but I like to warm and soften the bread slightly before making this hot sandwich.
- Spread the top side of each roll with horseradish mayo. Place caramelized onions on the bottom of each roll. Top the onions with slices of steak. Season with a sprinkle of salt and pepper. Smash the rolls together. Slice down the center on a slight diagonal and serve with warm jus. Wheeeew it’s good.