Roast Beef & Horseradish Sourdough Sandwich Recipe
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Roast Beef & Horseradish Sourdough Sandwich
Tender roast beef, creamy horseradish sauce, melted cheese, crisp onion, and fresh greens piled onto toasted sourdough. Bold, savory, and absolutely not a shy little sandwich.
Roast beef and horseradish are one of those combinations that already know exactly what they're doing.
The beef is rich and savory, the horseradish brings a sharp little kick, melted provolone adds creaminess, and crisp red onion and fresh greens keep the whole sandwich from becoming one uninterrupted pile of richness.
Put all of that onto toasted sourdough and you've got a sandwich with enough flavor for dinner, enough simplicity for lunch, and just enough horseradish to remind your sinuses that they are still employed.
🥩 Roast Beef & Horseradish Sourdough Sandwich
Tender roast beef, creamy horseradish sauce, melted provolone, crisp red onion, greens, and toasted sourdough.
🥪 Ingredients
- 4 thick slices sourdough bread
- 8 ounces thinly sliced roast beef
- 4 slices provolone or Swiss cheese
- 1/4 small red onion, very thinly sliced
- 1 cup arugula or mixed greens
- 1 tablespoon softened butter or olive oil for toasting the bread
- Freshly ground black pepper, to taste
For the Creamy Horseradish Sauce
- 1/4 cup mayonnaise
- 1 1/2 tablespoons prepared horseradish
- 1 teaspoon Dijon mustard
- 1 teaspoon fresh lemon juice
- Pinch of kosher salt
🔥 How to Make It
-
Make the horseradish sauce.
Stir together the mayonnaise, prepared horseradish, Dijon, lemon juice, and a pinch of salt. Taste and add more horseradish if you would like the sandwich to make stronger eye contact. -
Toast the sourdough.
Lightly butter or brush the bread with olive oil and toast in a skillet until golden and crisp around the edges. -
Warm the roast beef.
Add the roast beef to a skillet over low heat for about 30–60 seconds, just until warmed. Avoid cooking it until it becomes dry and starts filing complaints. -
Melt the cheese.
Divide the warm roast beef into two piles, top each with two slices of provolone or Swiss, and cover the skillet briefly until the cheese melts. -
Spread the sauce.
Spread a generous layer of creamy horseradish sauce over two slices of toasted sourdough. -
Build the sandwiches.
Add the cheesy roast beef, thinly sliced red onion, and fresh greens. Finish with black pepper to taste. -
Close and serve.
Top with the remaining sourdough slices, press gently, slice in half, and serve while the beef and cheese are still warm.
🌶️ Horseradish Has Opinions
Prepared horseradish can vary dramatically in strength, so start with the amount in the recipe and taste the sauce before adding more.
You want enough heat to cut through the roast beef and cheese, but ideally not so much that the first bite temporarily resets your vision.
🍞 Why Sourdough Is Perfect with Roast Beef
Roast beef, cheese, and creamy sauce are rich ingredients, so this sandwich needs bread with flavor and texture of its own.
Sourdough's natural tang works beautifully with sharp horseradish and Dijon, while the chewy crumb stands up to a generous stack of beef.
Toasting the sourdough adds the crispness that makes the soft roast beef and melted cheese even better.
Basically, if the sandwich is bringing eight ounces of roast beef, the bread should arrive prepared.
🏆 Four Ways to Make It Better
🥩 Slice the Beef Thin
Thin roast beef makes the sandwich easier to bite and keeps you from pulling half the filling out with one enthusiastic mouthful.
🧀 Melt the Cheese on the Beef
Letting the cheese melt directly over the warm roast beef gives you better coverage and keeps the sandwich warm.
🧅 Slice the Onion Very Thin
Red onion should bring sharp crunch, not completely take over the sandwich like it bought the building.
🌿 Add Fresh Greens
Arugula or mixed greens add freshness and a little peppery bite against the rich beef and creamy sauce.
🤤 Roast Beef Sandwich Variations
The beef-and-horseradish combination is already doing excellent work, but there are several ways to take it further.
- Add caramelized onions
- Swap provolone for Swiss or sharp cheddar
- Add roasted mushrooms
- Add crispy fried onions
- Add sliced pickles
- Use arugula for extra peppery flavor
- Add a little Worcestershire sauce to the horseradish spread
- Press the sandwich in a skillet for a warm, crispy version
🐿️ Squirrelly Girl Warning
There is a very specific moment when horseradish goes from “nice little kick” to “I can suddenly hear colors.”
Add accordingly.
🥪 Keep Exploring the Squirrelly Girl Sandwich Series
If big, savory beef sandwiches on toasted sourdough are your thing, these need to be next.
Tender roast beef, melted cheese, caramelized onions, and rich au jus for dipping. 🥩 Steak & Caramelized Onion Sourdough Sandwich
Juicy sliced steak, sweet caramelized onions, melted cheese, and crispy sourdough. 🧀 Sourdough Philly Cheesesteak
Tender beef, caramelized onions and peppers, melted cheese, and toasted sourdough. 🥪 Explore the Entire Squirrelly Girl Sandwich Series
Browse all our sourdough sandwich recipes and find your next lunch obsession.
🐿️ Want to Make the Sourdough Too?
Roast beef and horseradish deserve bread with enough flavor and structure to keep up. Start baking your own tangy, chewy sourdough with Squirrelly Girl Sourdough Starter.
Meet Squirrelly Girl Starter →