French Dip Sandwich

This French dip sandwich can be made with a rump roast or a prime rib, and it is a great dinner that is quick and easy to put together. Slow-roast the beef, slice it thin, and dip it in a rich homemade au jus for a sandwich that beats anything from a deli.

A budget-friendly chuck roast works beautifully here too. It slices clean once it is chilled and soaks up the au jus just like a pricier cut. If roast beef is your thing, you might also like our slow cooker pot roast.

French Dip Sandwich

Ingredients

• Diamond R prime rib or rump roast
• Cracked black pepper
• Kosher salt

For the Au Jus

• Packet of au jus mix
• 1 tablespoon Better than Bouillon beef base (or 3 bouillon cubes)
• 1 onion, sliced
• 2 tablespoons garlic, minced
• 2 sprigs fresh thyme
• 2 tablespoons butter
• 2 tablespoons good olive oil
• Buns or deli rolls
• Provolone cheese (optional)

Directions

Cook the beef: Preheat your oven to 300 degrees F. Season the roast generously with salt and pepper on all sides. Roast until the internal temperature reaches 120 degrees F (the roast will continue cooking in the au jus). Remove the roast from the oven and let it cool completely. For best results, refrigerate it overnight.

Once the roast has cooled, slice it thinly, the way you would ask for it at a deli.

For the au jus: In a large pot, saute the sliced onions in a mixture of olive oil and butter until softened. Add the minced garlic, being careful not to burn it. Pour in 4 cups of water, then add the au jus packet, thyme, and Better than Bouillon. Season with a dash of pepper (do not add salt). Bring the mixture to a boil, then reduce the heat and let it simmer for about an hour to reduce the liquid and meld the flavors.

Build the sandwich: Toast the buns or rolls in the oven. Add the thinly sliced roast beef to the au jus a few pieces at a time to reheat, no more than a minute. Assemble the sandwich by layering the heated beef on the toasted bun. Add provolone cheese if desired. Place the assembled sandwiches back in the hot oven for a few minutes to melt the cheese.

Serve these with a scoop of homemade horseradish sauce for a little kick, and if you want to nail cooking beef to the right temperature, our guide on searing a perfect steak covers the thermometer basics that keep any cut from overcooking.

A Diamond R chuck roast is an affordable, richly marbled roast that slices beautifully for French dips. Pasture-raised and grain-finished on our family farm in Kansas, one animal per box, no antibiotics and no added hormones.

Enjoy your delicious roast beef sandwiches with homemade au jus!

Frequently Asked Questions

What is the best cut of beef for French dip sandwiches?

A slow-roasted rump roast, prime rib, or chuck roast all work well. Chuck roast is the most budget-friendly and slices clean once chilled. The key is roasting it low, cooling the beef, then slicing it thin against the grain the way a deli would.

Why do you chill the roast before slicing?

Chilling the roast overnight firms up the meat so you can slice it paper-thin without it falling apart. Thin slices reheat in seconds in the hot au jus and stay tender, which is exactly the texture you want in a French dip sandwich.

Can I make the au jus from scratch?

Yes. This recipe uses an au jus packet plus Better than Bouillon for depth, but you can build a from-scratch jus by simmering beef drippings with sauteed onion, garlic, thyme, and beef stock. Season with pepper and go easy on the added salt.

What should I serve with French dip sandwiches?

Crispy fries, a simple green salad, or kettle chips all pair well. A little horseradish sauce or melted provolone takes the sandwich over the top, and a cup of extra au jus on the side is a must for dipping.