Ultimate Prime Rib French Dip Sandwich

If you ask me, French dip sandwiches are comfort food at its finest.

This classic sandwich gets a special upgrade when you start with tender slices of leftover prime rib instead of regular roast beef. The meat sits on a crusty French roll that soaks up all those wonderful juices.

Each sandwich is loaded with melted provolone cheese and served alongside a bowl of rich, homemade au jus that’s perfect for dipping. It’s the kind of meal that makes everyone at the table smile when they see it coming.

It’s a no-fuss recipe that turns yesterday’s fancy dinner into today’s cozy lunch, and trust me – it might be even better the second time around.

What Kind of Roast Beef Should I Use?

While this recipe shines brightest with leftover prime rib, you’ve got several tasty options to work with. Prime rib brings the most flavor to the party, but a good quality roast beef from the deli counter will definitely get the job done. If you’re going the deli route, ask them to slice it thin but not shaved – you want enough substance to hold up to the hot jus. For the best results when using leftover prime rib or sirloin, slice it as thinly as possible while it’s cold (this makes getting those nice, thin slices much easier). Just make sure whatever cut you choose has some good marbling, as that extra fat means extra flavor in your sandwich.

Options for Substitutions

This sandwich recipe is pretty adaptable and you can make several swaps depending on what you have in your kitchen:

• Gruyere cheese: Don’t have Gruyere? Swiss cheese is the closest match, but provolone or white cheddar would also work really well here.
• Red wine: If you prefer not to use wine, just add extra beef stock and a splash of balsamic vinegar to get that same rich flavor.
• French rolls: While French rolls are classic, you can use hoagie rolls, Italian bread, or even a crusty baguette. Just make sure whatever bread you choose is sturdy enough to hold up to dipping.
• Dijon mustard: Regular yellow mustard works in a pinch, or try whole grain mustard for a different texture. If you’re not a mustard fan, you can leave it out.
• Roast beef: While prime rib makes this sandwich extra special, you can use any leftover roast beef, or even good quality deli roast beef. Just warm it slightly before adding to your sandwich.
• Butter: You can swap butter with olive oil, but butter really does give the best flavor. If using beef drippings, they’ll add an extra beefy punch to your au jus.

Watch Out for These Mistakes While Cooking

The biggest mistake when making French dip sandwiches is rushing the au jus preparation – take your time to properly develop the flavors by letting the sauce simmer for at least 10-15 minutes, allowing the wine to reduce and the ingredients to meld together. A common error is using cold roast beef straight from the fridge, which can prevent the cheese from melting properly – instead, let your meat come to room temperature or quickly warm it in the au jus before assembling. To avoid soggy bread, make sure to toast your rolls until they’re golden brown and crispy, and serve the au jus on the side rather than pouring it directly over the sandwich. For the best melted cheese experience, place the assembled sandwiches under the broiler for 2-3 minutes, watching carefully to prevent burning, and let them rest for a minute before serving to allow the cheese to set slightly.

What to Serve With French Dip Sandwiches?

French dip sandwiches are pretty filling on their own, but adding a few sides can turn this into an amazing meal! A bowl of crispy French fries or potato chips works perfectly – they’re great for munching between bites of that juicy sandwich. If you want to keep things a bit lighter, try a simple coleslaw or a mixed green salad with a tangy vinaigrette dressing to cut through the richness of the meat and cheese. For something different, pickles or pepperoncini on the side add a nice zingy contrast to the savory beef and warm au jus.

Storage Instructions

Keep Fresh: If you’ve got leftover assembled sandwiches, wrap them tightly in aluminum foil and pop them in the fridge for up to 2 days. For best results though, I recommend storing the components separately – keep the au jus sauce in an airtight container, the meat in another, and use fresh rolls when you’re ready to eat.

Save the Au Jus: The au jus sauce can be kept in an airtight container in the fridge for up to 4 days. It’s actually even better the next day when the flavors have had time to develop! Just give it a good stir before reheating.

Warm Up: To enjoy your sandwich later, warm the au jus in a small pot over medium heat until hot. For the sandwich, wrap it in foil and heat in a 350°F oven for about 10-15 minutes, or until the cheese is melty again. The microwave works too, but the bread might get a bit soggy.

Preparation Time	15-20 minutes
Cooking Time	15-25 minutes
Total Time	30-45 minutes
Level of Difficulty	Medium

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 1800-2000
• Protein: 100-110 g
• Fat: 105-120 g
• Carbohydrates: 90-100 g

Ingredients

For the au jus:

• 1 tsp Worcestershire sauce
• 1 cup beef stock (I use Pacific Foods organic beef broth)
• 1/4 cup dry red wine (like Cabernet Sauvignon or Merlot)
• 1 tsp all-purpose flour
• 1 tsp Dijon mustard
• Ground black pepper to taste
• 1/4 tsp salt
• 2 tbsp butter (or beef pan drippings for richer flavor)

For the sandwich:

• 2 tbsp softened butter
• 4 oz shredded Gruyere cheese
• 2 French sandwich rolls (I like crusty baguettes for this)
• 1 lb thinly sliced roast beef

Step 1: Make the Au Jus

Begin by adding butter (or beef drippings, if using) to a saucepan and heat over medium-high heat.

Add flour and whisk to combine.

Allow the mixture to cook for several minutes until the flour is slightly browned.

Pour wine into the saucepan, whisking to combine, and allow it to cook for 1-2 minutes to let the alcohol burn off.

Add the remaining ingredients to the pan, stir to combine, and bring the mixture to a gentle simmer.

Step 2: Warm Meat in Au Jus

With the Au Jus on low heat, add the sliced meat just before you start making the sandwiches.

The goal is to warm the meat and let it soak up all the flavorful juices without overcooking it.

Keep the meat in the Au Jus until you’re ready to assemble the sandwiches.

Step 3: Prepare Sandwiches

Preheat the broiler to 500°F.

Place open sandwich rolls on a baking sheet and spread butter across the surface of each roll.

Broil the rolls until the butter melts and the edges of the bread begin to brown, then remove from the oven.

Using tongs, lift the meat from the Au Jus, shake off any excess liquid, and place it onto the rolls.

Cover the meat with shredded cheese.

Broil for about 5 minutes, or until the cheese is adequately melted.

Step 4: Serve

Carefully transfer the Au Jus to a dish with enough depth to allow for dipping.

Slice the sandwiches in half and serve them warm.

Delight in the rich flavors by dipping each bite of the sandwich into the Au Jus before eating.

Enjoy your juicy and savory creation!