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A sandwich made with slided prime rib, onions, and arugula on a baguette. French fries are next to the sandwich. a small wooden spoon with horseradish sauce is on the counter in front of the sandwich on the right.
5 from 4 votes

Prime Rib Sandwich

To make the perfect prime rib sandwich, layer leftover prime rib, expertly caramelized onions, arugula, and a tangy homemade horseradish sauce on a fresh baguette.
Author Diana
Servings 4 4-inch sandwiches
Prep Time 5 minutes
Cook Time 20 minutes
Total Time 25 minutes

Ingredients

  • 2 tablespoons olive oil
  • 2 medium yellow or white onions thinly sliced
  • 1 baguette
  • ½ cup horseradish sauce Use leftovers from your prime rib dinner or follow the recipe included below
  • 1 pound cooked prime rib sliced thinly and fat trimmed
  • 2 cups arugula wild rocket in the UK, or any other greens

Horseradish sauce

  • ¼ cup sour cream
  • 1 tablespoons prepared horseradish
  • 1 tablespoons mayonnaise
  • ½ teaspoon apple cider vinegar
  • ½ teaspoon Dijon mustard
  • ½ tablespoon chopped chives
  • ¼ teaspoon salt
  • ⅛ ground black pepper

Instructions

  • If you need to make fresh horseradish sauce, combine the sauce ingredients in a small bowl, and set aside.
  • To caramelize the onions, heat olive oil in a pan over medium heat. When the oil is hot, add the onions, cook the onions but keep stirring them (gently) all the time to caramelize them. This takes about 20 minutes.
  • In a pan warm up the prime rib briefly so it does not change color, this step is optional.
  • Take the baguette, remove the ends, and slice into 4 inch pieces. Slice in half lengthwise to open them up.
  • Spread horseradish sauce over each piece of baguette (top and bottom), then add sliced prime rib, followed by caramelized onions, and arugula. Finish off with a sprinkling of ground black pepper and serve.

Notes

  • You don't have to use prime rib. This sandwich will be just as delicious made with any type of leftover roast beef!
  • Plan Ahead. While you're picking up the prime rib from the store, grab a baguette and some fresh arugula so you'll be ready to make these sandwiches the next day.
  • Slice Cold. Prime rib is much easier to slice thinly when it's cold, rather than when it's warm from the oven.
  • Variations: Add thinly sliced tomatoes seasoned with salt and pepper, or make a hoagie-style prime rib sandwich by layering the meat with garlic mayo, tomato, lettuce, and provolone cheese. 
  • Other Greens: Use baby spinach, chopped romaine, or any other greens you enjoy in place of the arugula if you'd like. 

Nutrition

Serving: 14-inch sandwich | Calories: 656kcal | Carbohydrates: 40g | Protein: 23g | Fat: 45g | Saturated Fat: 16g | Polyunsaturated Fat: 4g | Monounsaturated Fat: 20g | Trans Fat: 0.01g | Cholesterol: 79mg | Sodium: 762mg | Potassium: 550mg | Fiber: 4g | Sugar: 9g | Vitamin A: 348IU | Vitamin C: 14mg | Calcium: 138mg | Iron: 4mg
Find it online: https://littlesunnykitchen.com/prime-rib-sandwich/