The French Dip Sandwich Melt is a tasty twist on a classic favorite. It’s made with tender roast beef, melted cheese, and lots of caramelized onions piled high on a soft, toasted bun. What really sets it apart is the rich, flavorful au jus sauce that you dunk each bite into, making every mouthful juicy and delicious.
I love making this sandwich when I want something hearty but easy to enjoy. The combination of melty cheese and juicy beef with the mild sweetness from the onions always hits the spot for me. One of my favorite tricks is to let the sandwich sit for a minute before serving so the cheese gets nice and gooey.
When I serve the French Dip Sandwich Melt, I like to put the au jus in little bowls for everyone to dip their sandwiches. It’s such a fun, casual way to eat and everyone seems to appreciate the saucy goodness. This sandwich is perfect for a cozy weekend lunch or a relaxed dinner with friends and family.
Key Ingredients & Substitutions
Roast Beef: Thinly sliced roast beef is key for tender, juicy sandwiches. Leftover roast or deli-style works great. For a leaner option, try turkey or chicken slices.
Onions: Caramelized onions add sweetness and depth. Yellow onions are best, but sweet onions or even shallots can be nice substitutes.
Provolone Cheese: Provolone melts beautifully and has a mild flavor. Swiss cheese is a great alternative if you want a nuttier taste.
Beef Broth & Worcestershire Sauce: These make the au jus rich and flavorful. Use low-sodium broth to control saltiness. Missing Worcestershire? Soy sauce adds a similar umami touch.
Bread: Soft sandwich rolls or baguettes work well. Choose sturdy bread that can hold the beef and sauce without getting soggy too quickly.
How Do You Caramelize Onions Perfectly for Maximum Flavor?
Caramelizing onions slowly is essential for that sweet, rich flavor. Rushing this step won’t give you the same results. Here’s how to get it right:
- Heat olive oil or butter in a skillet over medium-low heat.
- Add thinly sliced onions with a pinch of salt to help release moisture.
- Cook slowly, stirring every few minutes, until they turn golden brown and soft – about 15 to 20 minutes.
- If onions start to stick or brown too fast, reduce heat and add a splash of water to loosen them.
- Patience pays off! This step builds deep flavor that makes your French Dip special.
Equipment You’ll Need
- Skillet – perfect for caramelizing onions and warming the roast beef evenly.
- Small saucepan – makes it easy to simmer and reduce the au jus without mess.
- Baking sheet – use it to broil the assembled sandwiches so the cheese melts perfectly.
- Knife – for slicing onions and sandwich rolls precisely.
- Tongs or spatula – helps you handle the warm beef and onions without breaking them up.
Flavor Variations & Add-Ins
- Swap roast beef for sliced turkey or chicken for a lighter, milder sandwich.
- Try Swiss or mozzarella cheese instead of provolone for different meltiness and taste.
- Add sautéed mushrooms with onions for an earthy flavor boost.
- Mix a few dashes of hot sauce or horseradish into the au jus for a spicy kick.
French Dip Sandwich Melt
Ingredients You’ll Need:
Main Ingredients:
- 1 lb thinly sliced roast beef (leftover roast beef or deli roast beef works)
- 1 large onion, thinly sliced
- 2 tbsp olive oil or butter
- 4 slices provolone cheese (or Swiss cheese)
- 4 sandwich rolls or baguette halves
- 2 cups beef broth (preferably low sodium)
- 1 tsp Worcestershire sauce
- ½ tsp garlic powder
- Salt and pepper to taste
- Fresh parsley (optional, for garnish)
- Butter (for toasting the bread)
How Much Time Will You Need?
You’ll spend about 30 minutes preparing this delicious sandwich melt. Most of that time goes into slowly caramelizing the onions and warming up the beef and sauce. Toasting and assembling the sandwiches only takes a few minutes before a quick broil to melt the cheese perfectly. It’s a great meal that’s well worth the wait!
Step-by-Step Instructions:
1. Caramelize the Onions:
In a skillet over medium heat, warm the olive oil or butter. Add your thinly sliced onions with a pinch of salt and cook slowly, stirring every few minutes. Keep cooking until the onions are soft and golden brown, about 15-20 minutes. When done, set them aside for later.
2. Prepare the Au Jus Sauce:
Pour the beef broth into a small saucepan. Add Worcestershire sauce, garlic powder, salt, and pepper. Bring everything to a gentle simmer over medium heat and let it reduce slightly for about 10 minutes. Keep this warm—this delicious sauce will be your dipping treat!
3. Warm the Roast Beef:
Add the sliced roast beef to the pan with the caramelized onions. Stir gently just to warm everything together without breaking the beef slices apart.
4. Toast the Sandwich Rolls:
Slice your sandwich rolls or baguette in half. Lightly butter the cut sides, then toast them in a skillet or under the broiler until golden brown and crispy. This gives your sandwich a tasty crunch and prevents sogginess.
5. Assemble and Melt the Sandwich:
Pile a generous amount of the warm roast beef and onion mixture on the bottom half of each roll. Lay a slice of provolone cheese on top. Close the sandwich and place it on a baking sheet. Broil in the oven for 2-3 minutes, just enough to melt the cheese until it’s gooey and irresistible.
6. Serve and Enjoy:
Serve your French Dip Sandwich Melts hot on a plate with a small bowl of warm au jus sauce for dipping. Garnish with fresh parsley if you like. Dip each bite into the tasty broth and enjoy the comforting mix of flavors!
Can I Use Frozen Roast Beef for This Sandwich?
Yes! Just make sure to fully thaw the roast beef in the refrigerator overnight before using. This helps it warm evenly with the onions without becoming soggy.
Can I Make the Au Jus Ahead of Time?
Absolutely! You can prepare the au jus sauce a day in advance and refrigerate it. Reheat gently on the stove before serving, adding a splash of beef broth if it’s too thick.
How Should I Store Leftover Sandwiches?
Wrap leftovers tightly in foil or plastic wrap and store in the refrigerator for up to 2 days. Reheat in the oven or a skillet to keep the bread crispy and the cheese melty.
What’s the Best Bread for a French Dip Sandwich?
Soft sandwich rolls or a sturdy baguette work best to hold all the juicy beef and au jus without falling apart too quickly. Toasting the bread also helps prevent sogginess.
