A toasted French Dip Sandwich with melted Gruyère and a delicious homemade Au Jus is easy to make with leftover prime rib roast or deli meat! Thinly sliced beef is soaked in the Au Jus, then placed on a buttered toasted roll and topped with grated cheese and broiled in the oven. Absolutely delicious!
Why this recipe is so great:
- Fantastic use of leftover roast: If you've recently made a beef roast and you happen to have leftovers, you might be wondering how to use them. These sandwiches not only taste great, but they are easy to make and are one of the best ways to serve leftover roast. I've made these French Dip Sandwiches with my leftover Smoked Prime Rib but have also made them with my oven roasted prime rib roast.
- Works with sliced deli meat: Craving a French Dip Sandwich but don't have leftover sliced roast? No problem! Head to the deli and have them slice you some.
- Homemade Au Jus: Real Au Jus is just the cooking liquid created when braising, or slow cooking, meat. You can't enjoy a French Dip without Au Jus to dip it in, so you have two choices - buy the packet at the store or make homemade Au Jus. Not gonna lie; the Au Jus made from a packet tastes great, but if you take the time to look at the ingredients you'll want to make your own.
Exact quantities are listed in the recipe card below, but here is a summary.
- Roast beef: Can be from the deli or leftover from a home-cooked roast. For best results, thinly slice the meat.
- French rolls: These are found in the bread department of any major grocery store near the buns.
- Butter: I always recommend a high quality butter like Kerrygold.
- Gruyère cheese: One of the best melting cheese and the flavor is fantastic on a French Dip Sandwich.
- Au Jus: Homemade is always best, but you can also make from a packet.
For an extra kick, you can also make Horseradish Sauce to spread onto the sandwiches.
How to make French Dip Sandwiches:
Detailed step by step instructions are listed in the recipe card below, but here is a summary.
- Warm the meat: The trick with leftover prime rib is to warm the meat without cooking it. Simply have the Au Jus warming on the stove and add the thinly sliced meat. Maintain a temperature just below a simmer and only soak the meat as long as it takes to warm it.
- Toast the rolls: For the best flavor and also to prevent the bread from instantly getting soggy in the dipping Au Jus, cover it with a thin layer of butter and toast under the broiler.
- Add beef and cheese to rolls: Using tongs, pull the warmed sliced beef from the Au Jus, shake off any excess liquid, and add it to the rolls. Top the sliced roast beef with the grated Gruyere.
- Broil: Set the open-faced sandwiches under the broiler and heat until the cheese has melted.
Serve warm with individual portions of the Au Jus!
Recipe tips for perfect results:
- Thinly slice meat: These sandwiches are the most enjoyable when the meat is thinly sliced. Prime rib really does create the most mouthwatering sandwich because the meat is so tender and flavorful.
- Toast the bread well: If the bread isn't toasted well prior to making the sandwiches, it will fall apart. Be sure not to skip this step.
Other favorite sandwich recipes:
If you love a good homemade sandwich, be sure to check out these favorites.
- Leftover Prime Rib Sandwich - Not a French dip, but equally delicious
- Reuben Sandwich
- Open-faced Chicken Salad Sandwich
- Loaded Grilled Italian Sandwich
- California Club Sandwich
If you’ve made this or any other recipe on my site, let me know in the comment section how it turned out. I love hearing from my readers!
French Dip Sandwich
- 2 tablespoons butter (or drippings from beef roast)
- 1 teaspoon all-purpose flour
- ¼ cup red wine
- 1 cups beef broth
- 1 teaspoon Worcestershire sauce
- 1 teaspoon spicy brown mustard
- ¼ teaspoon salt (add more, to taste)
- freshly ground pepper (to taste)
French Dip Sandwiches:
- 2 French sandwich rolls (split)
- 2 tablespoons butter (softened)
- 1 pound roast beef (leftover prime rib or sirloin roast or from deli, thinly sliced)
- 4 ounces Gruyere (grated)
- Make Au Jus: Add butter (or beef drippings, if using) to saucepan and heat over medium-high heat. Add flour and stir with a whisk to combine. Allow to cook for several minutes to slightly brown the flour. Pour wine into pan, whisk to combine, and allow to cook for 1-2 minutes to allow the alcohol to burn off. Add remaining ingredients to the pan, stir to combine, and bring to a gentle simmer.
- Warm meat in Au Jus: Turn heat under Au Jus to low. Just prior to making the sandwiches, add the sliced meat to the Au Jus. The goal is to warm the meat and allow it to soak up all the flavor, but not to overly cook it.
- Prepare sandwiches: Preheat broiler to 500°F. Set open sandwich rolls on baking sheet and spread butter across surface. Broil until butter melts and edges of bread begin to brown, then remove from oven. Using tongs, remove meat from Au Jus, shake off any excess liquid, and place on rolls. Cover with shredded cheese. Broil for about 5 minutes, or just until cheese has melted.
- Serve: Transfer Au Jus to a dish with enough headroom to allow for dipping. Slice sandwiches in half and serve warm. To enjoy, dip each bite into Au Jus.