Copycat Arby’s Classic Roast Beef Sandwich

Why You’ll Love This Recipe

• Paper-thin, tender beef warmed gently in savory au jus—just like the classic sandwich shop version.
• Creamy, zippy “Horsey”-style sauce you can dial from mild to fiery.
• Fast weeknight method with deli roast beef or a weekend version from scratch.
• Simple pantry ingredients, big nostalgic flavor.

Grocery List

• Produce: Chives or flat-leaf parsley (optional garnish)
• Dairy: Unsalted butter (optional for buns)
• Pantry: Mayonnaise, prepared horseradish, sesame seed hamburger buns, low-sodium beef broth, Worcestershire sauce, soy sauce, white vinegar, apple cider vinegar, sugar, kosher salt, black pepper, onion powder, garlic powder

Full Ingredients

Horsey-Style Sauce

• 1/2 cup (120 g) mayonnaise
• 2 tbsp (30 g) prepared horseradish, drained
• 1 tsp (5 ml) distilled white vinegar
• 1 tsp (4 g) granulated sugar
• 1/4 tsp kosher salt (use half if using table salt)
• Pinch black pepper
• Optional: 1/4 tsp Dijon mustard for extra depth

Au Jus (Optional Dip)

• 2 cups (480 ml) low-sodium beef broth
• 1 tsp (5 ml) Worcestershire sauce
• 1 tsp (5 ml) soy sauce
• 1/2 tsp onion powder
• 1/4 tsp garlic powder
• 1/4 tsp ground black pepper
• 1 tsp (5 ml) apple cider vinegar
• 1 tsp (4 g) granulated sugar
• Optional body: 1 tsp (3 g) unflavored gelatin bloomed in 2 tbsp (30 ml) cold water

Sandwiches

• 1 lb (450 g) very thinly shaved roast beef (ask the deli for “paper-thin/shaved” top round)
• 4 sesame seed hamburger buns
• 2 tbsp (28 g) unsalted butter, softened (optional, for toasting)
• Prepared Horsey-Style Sauce (above)
• Optional garnish: 1 tbsp minced chives or parsley

From-Scratch Roast Beef (Optional)

• 2 lb (900 g) beef top round or eye of round
• 1 tbsp (12 g) kosher salt
• 1 tsp (4 g) sugar
• 1 tsp (2 g) onion powder
• 1/2 tsp garlic powder
• 1/2 tsp ground black pepper
• 1 tbsp (15 ml) neutral oil

Step-by-Step Instructions

Step 1: Mix the Horsey-Style Sauce

In a small bowl, combine mayonnaise, prepared horseradish, white vinegar, sugar, salt, and a pinch of black pepper (plus Dijon if using). Stir until smooth. Cover and let sit 10–20 minutes to mellow and bloom the horseradish flavor. Refrigerate if making ahead (up to 1 week).

Step 2: Make the Au Jus

In a small saucepan, combine beef broth, Worcestershire, soy sauce, onion powder, garlic powder, black pepper, apple cider vinegar, and sugar. Bring to a simmer over medium heat, then reduce to low and cook 5–10 minutes. For extra body, stir in bloomed gelatin until dissolved. Keep the au jus at a bare simmer (about 160–170°F) to warm the beef without overcooking.

Step 3: Warm the Shaved Beef Gently

Working in small handfuls, dip the paper-thin roast beef into the hot au jus for 30–60 seconds until just warmed and supple. Transfer to a plate and tent loosely with foil. Repeat until all portions are warmed. Do not boil—the goal is tender, not tough.

Step 4: Warm or Steam the Buns

For classic softness, steam buns over the au jus: set a steamer basket over the pot, add buns, cover, and steam 30–60 seconds until warm and fluffy. Alternatively, butter the cut sides and toast on a skillet over medium heat for 1–2 minutes until lightly golden.

Step 5: Build the Sandwiches

Spread 1–2 tablespoons Horsey-Style Sauce on the cut side of each top bun. Pile about 4 ounces of warm shaved roast beef on each bottom bun, letting some edges ruffle and fold for height. Cap with the sauced top bun. Sprinkle with minced chives or parsley if you like a fresh pop of color.

Step 6: Optional From-Scratch Roast Beef for Ultra-Thin Slices

Pat the 2 lb top round dry. Mix salt, sugar, onion powder, garlic powder, and pepper; rub all over. Refrigerate uncovered 8–24 hours for best flavor and even seasoning. When ready, preheat oven to 275°F (135°C). Heat oil in a skillet over medium-high and sear roast on all sides, 6–8 minutes total. Transfer to a rack set in a rimmed sheet pan and roast until the center reaches 125°F (52°C) for medium-rare, about 50–70 minutes depending on thickness. Rest 15 minutes, then chill completely (4 hours or overnight) for clean, paper-thin slicing. Shave the chilled roast across the grain—use a meat slicer if you have one, or partially freeze for 30 minutes to firm before slicing by hand. Warm slices in au jus as in Step 3.

Step 7: Serve with Au Jus

Serve sandwiches immediately with small ramekins of hot au jus for dipping. Keep remaining au jus warm over low heat and replenish as needed for second helpings.

Pro Tips

• Ask the deli to shave top round “as thin as possible.” The thinner the slice, the more tender the bite.
• Keep the au jus hot but not boiling. Gentle heat keeps the beef juicy and prevents toughness.
• For soft, classic buns, steaming beats toasting. If you prefer a little texture, lightly toast only the cut faces.
• Adjust Horsey heat by adding more or less prepared horseradish. For extra bite, stir in a touch of grated fresh horseradish.
• Gelatin in au jus adds a silky, beefy body that clings to the meat—highly recommended.

Variations

• Cheddar Melt: Add warm, smooth cheddar cheese sauce and serve on an onion roll.
• French Dip Style: Add a slice of Swiss and caramelized onions; serve with extra-hot au jus.
• Spicy Kick: Fold 1 tsp hot sauce or extra horseradish into the Horsey-Style Sauce.

Storage & Make-Ahead

Horsey-Style Sauce keeps up to 1 week refrigerated. Au jus can be refrigerated up to 4 days or frozen 2 months; reheat gently. Shaved cooked roast beef keeps 3–4 days chilled; warm in hot au jus just before serving. Buns freeze well; thaw at room temp and steam to refresh.

Nutrition (per serving)

Approximate per sandwich with 4 oz beef, bun, and 1.5 tbsp sauce: 540 calories; 27 g fat; 36 g carbohydrates; 31 g protein; 1,200–1,500 mg sodium. Values vary by brand and portion size.