Ingredients
Equipment
Method
- If your prime rib is cold, you can gently warm it in a skillet over medium-low heat with a tablespoon of water or beef broth, just until it’s no longer cold. Avoid overcooking it, as it will heat up again in the au jus. Slice the prime rib as thinly as possible against the grain for maximum tenderness. Set aside.1 to 1.5 pounds leftover prime rib
- In a large skillet or Dutch oven, melt the butter over medium heat. Add the thinly sliced onions and a pinch of salt. Cook, stirring occasionally, for about 15-20 minutes, or until the onions are deeply golden brown and softened. This slow caramelization brings out their natural sweetness.2 tablespoons unsalted butter, 1 large yellow onion, to taste salt
- Once the onions are caramelized, add the minced garlic to the skillet. Cook for another minute until fragrant, being careful not to burn it.2 cloves garlic
- If using red wine, pour it into the skillet with the onions and garlic. Scrape the bottom of the pan with a wooden spoon to loosen any browned bits. Let the wine simmer and reduce by about half, which will take 2-3 minutes. This adds a wonderful layer of flavor.1/2 cup dry red wine
- Pour in the beef broth and add the Worcestershire sauce and dried thyme. Bring the mixture to a simmer, then reduce the heat to low. Let it gently simmer for at least 10-15 minutes to allow the flavors to meld and deepen. Taste and season with salt and freshly ground black pepper as needed. The goal is a rich, savory broth.2 cups beef broth, 1 tablespoon Worcestershire sauce, 1 teaspoon dried thyme, to taste salt, to taste freshly ground black pepper
- While the au jus simmers, prepare your rolls. You can lightly toast them under the broiler, in a toaster oven, or in a dry skillet until golden and slightly crisp. This prevents them from getting too soggy when dipped.4 crusty submarine rolls or French baguettes
- Generously pile the thinly sliced leftover prime rib onto the bottom halves of the toasted rolls.1 to 1.5 pounds leftover prime rib, 4 crusty submarine rolls or French baguettes
- If you like a cheesy French Dip, place slices of Provolone or Gruyere cheese over the meat. You can place the open-faced sandwiches under the broiler for a minute or two until the cheese is melted and bubbly.Provolone or Gruyere cheese slices, 1 to 1.5 pounds leftover prime rib
- Place the top halves of the rolls onto the sandwiches. Serve immediately with small bowls of the hot au jus for dipping. Garnish with fresh chopped parsley, if desired.4 crusty submarine rolls or French baguettes, fresh parsley
Notes
Properly storing and reheating your delicious Leftover Prime Rib French Dip components will ensure you can enjoy this incredible meal again. It's best to store components separately for optimal texture. Refrigerate the sliced prime rib, caramelized onions, and the au jus in airtight containers. The au jus will keep for 3-4 days, while the cooked meat and onions are best consumed within 2-3 days.
To reheat, gently warm the sliced prime rib in a skillet over low heat with a splash of the au jus until heated through. Reheat the au jus in a saucepan over low heat until piping hot. Assemble your sandwiches with fresh or lightly toasted rolls and dip as usual. You can also freeze the au jus for up to 2-3 months. Thaw it completely in the refrigerator before reheating on the stovetop.