
Roast Beef Sandwich with Spicy Mayo Radishes
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This roast beef sandwich, made with either leftover roast beef or beef from the deli, is delicious. We top ours with thinly sliced radishes mixed with horseradish and mayo, which gives it the perfect crunch and flavor. You'll love it!
This sandwich goes great with our creamy cucumber salad. And if you love sandwich recipes, also try our chipotle orange pulled chicken sandwich!

Roast Beef Sandwich
Whether you're looking for a way to use some leftover roast beef, or you've made a trip to the deli, this is your sandwich.
It's as simple as it gets, yet somehow so much more than its parts.
- Tender, thin slices of roast beef.
- Crunchy radishes.
- Creamy horseradish mayo, because horseradish and roast beef is THE BEST combo.
- Capers for a salty treat.
- All tucked not so neatly inside a deliciously soft bun.
This is what lunch should look like! Or dinner. Or breakfast. Not making any judgments here!

What to put in a roast beef sandwich
Sandwiches don't tend to be picky things. But they are best when there are contrasting textures – a soft bun, creamy mayo, something crunchy.
We love to pile our roast beef sandwich high with our spicy radish salad. But there are lots of options!
- Add cheese – swiss is really good!
- Caramelized onions – yes!
- Ripe tomato slices
- Crunchy cucumbers
If you have leftover roasted veggies from your dinner, try adding some to the sandwich. It's surprisingly good!

How to make a roast beef sandwich
Basically, you're going to pile everything into a soft bun and call it lunch. But there are a few things to keep in mind.
- This sandwich is best if the beef is sliced thin. If you're doing this at home, take your time. It will never be as thin as the deli cuts it, but try to make it as thin as possible.
- Slather some mayo (dijon mustard is nice, too!) onto the bun.
- And choose a great bun. brioche buns and potato buns are both known to be very soft and delicious. Kaiser buns are another readily-available and decent option.
- Add some sort of crunch. It could be the radishes in this recipe, sliced cucumbers, or crunchy romaine hearts.

Favorite sandwich recipes
- Grilled Cheese and Apple Sandwich with Sriracha Butter
- Prosciutto, Blue Cheese and Candied Pecan Panini
- Oyster Po’ Boy with Sweet Onion Relish and Chipotle Aioli
- Grilled Cheese Sandwich with Bacon, Tomato and Basil

Roast Beef Sandwich Recipe
Ingredients
- 1 cup sliced radishes
- 2 tablespoons mayonnaise (plus extra for the bun, optional)
- 1 tablespoon prepared horseradish
- 2 teaspoons capers
- 4 soft buns – brioche or kaiser buns work well
- Arugula or remaine lettuce (for the buns)
- 8 ounces sliced roast beef
Instructions
- In a small bowl, combine the radishes, mayonnaise, horseradish, and capers.1 cup sliced radishes, 2 tablespoons mayonnaise, 1 tablespoon prepared horseradish, 2 teaspoons capers
- Spread mayonnaise on both sides of each bun and top with lettuce, roast beef, and the radishes.4 soft buns – brioche or kaiser buns work well, Arugula or remaine lettuce, 8 ounces sliced roast beef
Nutrition
We have thoroughly tested this recipe for accuracy. However, individual results may vary. See our full recipe disclosure here.
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