Ingredients
Equipment
Method
- In a small bowl, whisk together the sour cream, prepared horseradish, Dijon mustard, and lemon juice. Season with a pinch of salt and pepper. Taste and adjust the horseradish for your desired level of spice. Cover and refrigerate until ready to serve. This sauce adds a delightful kick and creamy counterbalance to the rich prime rib.1/2 cup sour cream, 2 tablespoons prepared horseradish, 1 teaspoon Dijon mustard, 1/2 teaspoon lemon juice, pinch salt and pepper
- Heat the olive oil or butter in a large skillet over medium heat. Add the thinly sliced yellow onion and cook, stirring occasionally, until softened and beginning to caramelize, about 8-10 minutes. If you want deeper flavor, you can let them cook longer until richly browned.1 tablespoon olive oil or unsalted butter, 1 medium yellow onion
- Add the minced garlic to the skillet with the onions and cook for another minute until fragrant, being careful not to burn the garlic. Pour in the beef broth (or red wine) and Worcestershire sauce. Stir to deglaze the pan, scraping up any browned bits from the bottom. Add the dried thyme, salt, and pepper. Bring to a simmer and let it cook for 2-3 minutes to allow the flavors to meld.2 cloves garlic, 1/2 cup beef broth or red wine, 1 tablespoon Worcestershire sauce, 1 teaspoon dried thyme, to taste salt and freshly ground black pepper
- Add the thinly sliced prime rib to the skillet with the onion mixture. Gently stir to coat the steak in the flavorful sauce. Cook for 3-5 minutes, or until the prime rib is heated through. Avoid overcooking, as this can make the steak tough. The residual heat will warm it perfectly.1 pound leftover cooked prime rib
- While the prime rib is warming, slice your sandwich rolls in half horizontally. You can lightly toast them under the broiler for a minute or two, or warm them in the oven if you prefer.4 high-quality sandwich rolls
- Spoon a generous amount of the saucy prime rib and onions onto the bottom half of each roll. If using, layer slices of provolone or Gruyere cheese over the hot steak and onions so they can melt slightly.1 pound leftover cooked prime rib, Provolone or Gruyere cheese slices
- Spread a generous dollop of the prepared horseradish cream sauce on the top half of each roll. Add any optional toppings like fresh arugula or spinach.1/2 cup sour cream, fresh arugula or spinach
- Place the top half of the roll onto the bottom half, gently press down, and serve your delicious Prime Rib Steak Sandwiches immediately.
Notes
Leftover ingredients can be stored separately for up to 3 days. Reheat prime rib mixture gently in a skillet. Warm rolls separately. Assemble just before serving to prevent sogginess. Freeze prime rib mixture separately for up to 2 months.