The French Dip Sandwich Melt is a delicious twist on a classic favorite. It features thinly sliced roast beef piled high on a toasted sandwich roll, melted cheese dripping over every bite, and a side of warm, savory au jus for dipping. The sandwich is crispy on the outside, tender and juicy on the inside, making every mouthful a perfect balance of textures and flavors.
I love making this sandwich when I want something that feels both comforting and a little bit special. One of my favorite tips is to soak the bread lightly in the au jus before adding the beef and cheese, which keeps everything extra juicy and flavorful. It’s one of those meals that feels like a treat but comes together easily, which is a win in my book.
French Dip Sandwich Melts are great for lunch or dinner, especially when served alongside crispy fries or a fresh green salad. I also find that sharing this meal with family or friends makes it feel even better, since everyone loves dunking their sandwiches and savoring those warm, tasty juices. It’s a simple pleasure that always hits the spot.
Key Ingredients & Substitutions
Roast Beef: Thinly sliced, tender roast beef is the star here. If you can’t find it pre-sliced, roast a small beef eye round or sirloin and slice it very thin. Leftover roast beef works well, too.
Provolone Cheese: Provolone melts beautifully and adds mild creaminess. You can swap with mozzarella, Swiss, or even Monterey Jack if you prefer.
Sandwich Rolls: Ciabatta or French rolls are best for that crispy outside and soft inside. If you don’t have these, a sturdy hoagie or baguette works fine.
Au Jus: Beef broth plus Worcestershire sauce makes a simple, flavorful dipping sauce. No beef broth? Try beef bouillon cubes dissolved in water as a quick fix.
Caramelized Onions: They add sweet depth without overpowering. Yellow onions are my favorite here — they get lovely and sweet when cooked low and slow.
How Do I Get Perfectly Caramelized Onions for This Sandwich?
Caramelized onions bring a soft, sweet flavor that balances the savory beef. Here’s how to make them melt in your mouth:
- Cook onions over medium-low heat with a bit of oil and a pinch of salt to help them sweat.
- Stir often, scraping up any browned bits so they don’t burn — patience is key here.
- After 20-25 minutes, they’ll turn golden and soft, packed with natural sweetness perfect for the sandwich.
- If you’re in a hurry, stirring more frequently at medium heat helps but be careful not to burn them.
Equipment You’ll Need
- Skillet – perfect for caramelizing onions evenly without burning.
- Small saucepan – you’ll use this to simmer the au jus and blend flavors.
- Griddle or heavy skillet – to toast the sandwich rolls until crispy and golden.
- Baking sheet or oven-safe dish – for melting the cheese under the broiler quickly.
- Tongs – handy for assembling and handling hot sandwich parts.
Flavor Variations & Add-Ins
- Swap roast beef for sliced turkey or chicken for a lighter twist that still pairs well with au jus.
- Use Swiss or mozzarella cheese instead of provolone for a different melt and flavor.
- Add sautéed mushrooms along with onions for extra earthiness and texture.
- Try a spread of horseradish mayo or Dijon mustard inside the roll for a tangy kick that cuts the richness.
How to Make a French Dip Sandwich Melt
Ingredients You’ll Need:
Main Ingredients:
- 1 lb thinly sliced roast beef (preferably tender and cooked medium rare)
- 4 ciabatta or French sandwich rolls
- 8 slices provolone cheese
- 2 tbsp butter, softened
- 1 large onion, thinly sliced
- 1 tbsp olive oil
- 2 cups beef broth (for au jus)
- 1 tsp Worcestershire sauce
- 1 garlic clove, minced
- ½ tsp dried thyme
- Salt and pepper, to taste
- Fresh parsley, chopped (optional, for garnish)
How Much Time Will You Need?
This recipe takes about 35-40 minutes in total. You’ll spend about 20-25 minutes caramelizing the onions, 10 minutes simmering the au jus, and a few minutes to assemble, toast, melt the cheese, and finish the sandwiches.
Step-by-Step Instructions:
1. Caramelize the Onions:
Heat olive oil in a skillet over medium heat. Add the thinly sliced onions and a pinch of salt. Cook slowly, stirring often, until the onions turn golden and caramelized. This should take about 20 to 25 minutes. When done, set aside.
2. Make the Au Jus:
In a small saucepan, combine beef broth, Worcestershire sauce, minced garlic, dried thyme, salt, and pepper. Bring to a simmer over medium heat, letting it cook for about 10 minutes to let the flavors blend. Keep warm on low heat.
3. Prepare and Toast the Sandwich Rolls:
Slice each sandwich roll in half. Spread softened butter on the outside of the bread slices. Heat a griddle or skillet over medium heat and toast the buttered sides until golden brown and crispy. Remove from heat.
4. Assemble and Melt the Sandwich:
Lay thin slices of roast beef on the bottom halves of the toasted rolls. Top each pile with 2 slices of provolone cheese, and spoon a generous amount of caramelized onions on top. Place the assembled bottoms under a broiler for 2-3 minutes, or in a hot oven until the cheese melts and bubbles.
5. Finish and Serve:
Remove the sandwiches from the oven and place the toasted top halves on each. Garnish with chopped parsley if you’d like. Serve immediately with small bowls of the warm au jus for dipping. It’s delicious dipped or eaten as is!
Can I Use Frozen Roast Beef for the Sandwich?
Yes, you can use frozen roast beef, but be sure to fully thaw it in the refrigerator overnight first. This will help it slice thinly and reheat evenly in the sandwich.
Can I Make the Au Jus Ahead of Time?
Absolutely! The au jus can be made a day ahead and refrigerated. Simply reheat gently on the stove before serving to keep it warm and flavorful.
How Should I Store Leftovers?
Store leftover sandwiches and au jus separately in airtight containers in the refrigerator for up to 2 days. Reheat the sandwich in a 350°F oven wrapped in foil, and warm the au jus on the stovetop or microwave before serving.
Can I Substitute Another Cheese?
Yes! Swiss, mozzarella, or Monterey Jack all melt well and provide great flavor if you want to switch up from provolone.
