How to Perfectly Heat Up Roast Beef for French Dip Sandwiches

French dip sandwiches are a delicious meal that combines tender slices of roast beef, melty cheese, and a flavorful au jus dipping sauce. While you can use leftover roast beef, heating it up properly is key to creating the ideal French dip experience In this article, I’ll walk you through exactly how to heat up roast beef to make incredible French dip sandwiches at home.

Choose the Right Roast Beef

For French dips you want to use a tender, thinly sliced roast beef. Top round or bottom round roasts work best. If you’re starting with a roast slice it as thinly as possible across the grain. For even thinner slices, have your butcher slice it for you or freeze the roast for 30-60 minutes before slicing.

If you don’t have a leftover roast high-quality deli roast beef is a convenient shortcut. Look for roast beef sliced fresh in-store. Pre-packed roast beef tends to be lower quality. For ultimate flavor and tenderness, opt for rare or medium rare roast beef.

Heat Roast Beef in the Oven

One of the best ways to evenly reheat large batches of roast beef is in the oven. Here’s how:

  • Preheat oven to 300°F.

  • Place roast beef slices in a single layer on a baking sheet.

  • Heat for 10-15 minutes until warmed through. Thinner slices of meat may only need 7-10 minutes.

  • Check frequently and remove once hot. Overcooking can make the roast beef dry.

The ambient heat of the oven warms the beef without overcooking it. For added flavor, sprinkle with a bit of salt and pepper before heating.

Use the Stovetop to Heat Small Batches

If you just need to heat up a few slices of roast beef, the stovetop offers faster results:

  • Heat 1 tsp oil in a skillet over medium-high heat.

  • Add roast beef slices in a single layer and cook for 1-2 minutes per side, until hot.

  • Use metal tongs to flip beef and avoid piercing it.

  • Cook just until heated through to prevent toughness.

The direct heat quickly warms up the small amount of meat. Use a nonstick pan for easiest release.

Microwave for Quick Reheating

The microwave can also reheat roast beef in a hurry:

  • Place beef slices on a microwave-safe plate in a single layer.

  • Microwave on HIGH for 30 seconds to 1 minute.

  • Check frequently to avoid overcooking.

  • Allow to rest 30 seconds before assembling sandwiches.

When microwaving meat, use short cooking times to retain moisture. Let the meat rest before eating so juices can redistribute.

Maintain Moisture While Reheating

Roast beef can dry out quickly when reheated. Follow these tips for moist results:

  • Cover beef loosely with foil when using the oven or microwave. This traps in steam.

  • Add a splash of beef broth to the dish or plate before heating.

  • Watch meat closely and stop heating as soon as it’s hot.

  • Allow meat to rest 5 minutes after reheating so juices redistribute.

  • Add au jus sauce to the meat after reheating for a moisture boost.

Make the Au Jus Sauce

An incredible au jus sauce takes French dip sandwiches to the next level. To make it:

  • In a saucepan, combine 2 cups beef broth and 1 tsp Worcestershire sauce.

  • Add seasonings like garlic powder, onion powder, thyme, and bay leaves.

  • Simmer 20 minutes until reduced by half.

  • Thicken with a cornstarch slurry if desired.

  • Strain out solids and adjust seasoning to taste.

You can also use the flavorful juices leftover from cooking your roast beef. For convenience, high quality pre-made au jus can substitute.

Assemble Perfect French Dip Sandwiches

Once your roast beef is heated, it’s time for assembly:

  • Slice a French roll or baguette horizontally.

  • Add roast beef slices and top with cheese like provolone or mozzarella.

  • Place on a sheet pan and broil 3-5 minutes until cheese is melted.

  • Serve au jus sauce alongside for dipping.

Make sure your bread can stand up to the juicy meat and sauce. Baguettes, French rolls, or hearty sourdough work well.

For added flavor, sauté onions or mushrooms to add to the sandwich before broiling. Slice bread on a bias for a striking presentation.

Reheating Leftover French Dip Sandwiches

Have leftover French dip sandwiches? They reheat beautifully:

  • Wrap sandwich halves individually in foil.

  • Heat in a 300°F oven for 10 minutes until hot.

  • Or reheat 1-2 minutes per side in a skillet over medium heat.

  • Microwave 30 seconds at a time, checking frequently.

  • If bread is soggy, toast briefly under the broiler before serving.

A brief stint in the oven or skillet makes leftover French dips taste like they were just made. The foil helps steam the sandwich to perfection.

Tips for French Dip Success

Follow these tips and tricks for mouthwatering French dip sandwiches:

  • Let roast beef rest after cooking for easier slicing across the grain. Chill in fridge before slicing.

  • Add some cooking liquid or au jus to the meat while reheating for extra moisture.

  • Constantly check meat while reheating to avoid overcooking.

  • Allow meat to rest after reheating so juices redistribute evenly.

  • Get creative with cheese choices like smoked gouda or havarti.

  • Dip the top side of your sandwich so the bottom bun doesn’t get too soggy.

  • Offer au jus on the side for dipping instead of pouring it directly on the sandwich.

  • Slice your French roll on a bias for a beautiful presentation.

Reheating roast beef properly and taking care to keep it moist is the key to French dip perfection. With tender rare beef, incredible au jus, and melty cheese on a crispy baguette, you’ll feel like you’re dining at a gourmet bistro. Use these tips to elevate your French dip game at home. Your family will be begging for second helpings.

Classic French Dip Recipe


How do you reheat roast beef in au jus?

Stovetop: Pour au jus into a heavy bottomed pot set at medium heat. Cover, & heat gently for about 10 minutes stirring occasionally. Add roast beef to the au jus after it’s warmed, but no need to cook it, just heat through.

How do you heat up deli sliced roast beef?

Preheat oven to 400 degrees. Wrap the roast beef deli slices in foil. Using two foil packs will heat the meat up quickest. Place the deli meat in oven for 15 minutes.

How do you reheat prime rib for French dip?

Place the leftover roast in a pan and cover with foil. To retain the succulent quality of the meat, add a little au jus from the previous day, or add 1/4 cup of low-sodium beef stock. Place in an oven preheated to 300 degrees F (150 degrees C) for approximately 20 to 30 minutes, depending on the size of the piece.

How do I cook a beef roast without drying it out?

When cooking a roast in the oven, keep it uncovered until roasted to the desired doneness. After removing from the oven, tent with foil and let stand 15 minutes before carving. This allows the juices to redistribute, preventing them from draining out during carving—and preventing dry, disappointing meat.

Can you make French dip with rump roast?

BEEF Most French dip recipes are made with chuck or rump roast. The beef cooks until tender and we find it easiest to pull the beef into big chunks instead of cutting it. As long as it is braised in liquid and extra tender, it will be perfect in French dips! AU JUS This is the juices in the slow cooker we use for dipping.

How long do you cook a French dip sandwich?

Bake, uncovered, for 10 minutes in a preheated 350 degree oven. Remove the sandwiches from the oven, piling on caramelized onions and creamy horseradish, then topping with the buns with cheese. Serve the French dip sandwiches with warm au jus on the side for dipping.

How do you cook a roast beef sandwich?

Place roast beef in broth and warm for 3 minutes. Arrange meat on hoagie rolls and top each roll with 2 slices of provolone. Bake sandwiches in the preheated oven until cheese melts, about 5 minutes. Serve sandwiches with small bowls of warm broth for dipping.

Can you use burger buns in French dip?

Even heavy burger buns will do in a pinch! BEEF Most French dip recipes are made with chuck or rump roast. The beef cooks until tender and we find it easiest to pull the beef into big chunks instead of cutting it. As long as it is braised in liquid and extra tender, it will be perfect in French dips!

Leave a Comment