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leftover beef prime rib sandwiches ciabatta bread caramelized onions
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4.50 from 2 votes

Leftover Prime Rib Sandwich

Incredible beef prime rib sandwiches filled with sweet caramelized onions and melted cheese on toasted ciabatta bread.
Prep Time5 minutes
Cook Time40 minutes
Total Time45 minutes
Course: Leftovers, Main Course
Cuisine: American
Servings: 4 sandwiches
Author: Ben Isham-Smith

Equipment

Ingredients

  • 1 lb smoked prime rib
  • 1 white onion sliced
  • 1 tsp kosher salt
  • 2 loaves ciabatta bread
  • 8 slices provolone cheese
  • 2 cups arugula
  • 4 tbsp horseradish mustard

Instructions

  • Preheat oven to 250°F (120°C)
  • Heat oil in a cast-iron skillet over low heat. Add chopped onions and a pinch of salt. Stirring occasionally, heat until they are soft and golden. 30-40 minutes.
  • While onions caramelize, move onto the beef. Line a small baking pan with aluminum foil and add a couple of splashes of cooking spray. Place the prime rib on the pan and cover with foil. Warm in the oven for 10-15 minutes, until beef is warmed through.
  • Remove prime rib from oven and carve into thin slices
  • Slice ciabatta bread lengthwise at a 45-degree angle into halves. Arrange provolone slices on one-half of each sandwich.
  • Toast ciabatta under the broiler on high heat for 2-3 minutes, until the provolone starts to melt.
  • Remove bread from the broiler and arrange each sandwich with warmed prime rib slices, caramelized onions, arugula, and horseradish mustard. Serve and enjoy immediately.