The French Dip Sandwich Melt is a classic comfort food that combines juicy, thinly sliced roast beef with melted cheese on a toasted roll. The standout feature is the warm, savory au jus sauce that you dip your sandwich into, making each bite juicy and full of flavor. It’s a simple but delicious combo that feels like a little celebration in every sandwich.
I love making this sandwich because it’s so easy to put together but still feels special. There’s something satisfying about the melted cheese stretching as you take a bite, and the tender beef just soaks up the au jus perfectly. I usually like to add a little horseradish sauce for a bit of a kick, but it’s just as tasty plain.
My favorite way to enjoy a French Dip Sandwich Melt is fresh out of the oven with a side of crispy fries or a light salad. It’s the kind of meal that warms you up on a cool evening and makes the whole family smile. Plus, dipping that melty sandwich into the savory broth is a small but wonderful moment I look forward to every time.
Key Ingredients & Substitutions
Roast beef: Thin slices of good quality roast beef give the sandwich its rich taste. If you can’t find roast beef, thinly sliced deli roast beef or leftover roast works well. Just keep it tender and not too dry.
Provolone cheese: This cheese melts beautifully without overpowering the beef. Swiss or mozzarella are good substitutes if you want a milder or creamier melt.
Beef broth: The base for the flavorful au jus sauce. Low sodium broth lets you control the saltiness. You can also use beef stock or even a mix of broth and drippings from cooked beef for deeper flavor.
Onions: Caramelized onions add sweet depth. Yellow onions are ideal, but white onions work too. Avoid raw onions here, as the slow cook brings out a mellow flavor.
How Can I Make Perfect Caramelized Onions for My Sandwich?
Caramelizing onions slowly draws out their sweetness and softens their texture, which makes a big difference in flavor. Here’s how I do it:
- Melt butter over medium-low heat in a skillet.
- Add thinly sliced onions and stir to coat with butter.
- Cook slowly, stirring occasionally, for 20-25 minutes until golden brown.
- Be patient—it’s the slow cooking that turns onions sweet, not heat.
- If onions start sticking, add a splash of water to loosen them.
Caramelized onions give a wonderful balance to the savory roast beef and melted cheese in the sandwich.
Equipment You’ll Need
- Medium skillet – perfect for slowly caramelizing the onions without burning them.
- Small saucepan – to gently simmer the au jus sauce and blend the flavors.
- Baking sheet – great for broiling the sandwiches so the cheese melts evenly.
- Sharp knife – makes slicing the rolls easy and keeps them intact for filling.
- Cutting board – a stable surface for preparing ingredients safely.
Flavor Variations & Add-Ins
- Swap roast beef for thinly sliced turkey or ham for a different but tasty twist.
- Use Swiss or mozzarella cheese if you want a milder or creamier melt.
- Add sautéed mushrooms with the onions for extra depth and texture.
- Mix in a spoonful of horseradish sauce or Dijon mustard for a bit of zing.
How to Make a French Dip Sandwich Melt
Ingredients You’ll Need:
For the Sandwich:
- 1 lb thinly sliced roast beef (from a good quality cooked roast)
- 4 hoagie rolls or French bread rolls
- 1 cup provolone cheese slices
- 2 tablespoons butter, softened
- 1 large onion, thinly sliced
For the Au Jus Sauce:
- 2 cups beef broth (preferably low sodium)
- 1 tablespoon Worcestershire sauce
- 1 teaspoon garlic powder
- ½ teaspoon onion powder
- Salt and pepper to taste
Optional Garnish:
- Fresh parsley, chopped
Time Needed
This recipe takes about 35-40 minutes total. Caramelizing the onions needs about 20-25 minutes, preparation and assembly takes around 10-15 minutes, and broiling the sandwich only a few minutes. You can prepare the au jus sauce quickly while the onions cook.
Step-by-Step Instructions:
1. Caramelize the Onions:
Start by melting 1 tablespoon of butter in a medium skillet over medium-low heat. Add the thinly sliced onions and cook them slowly, stirring every few minutes, until they become soft and deeply golden — this usually takes around 20 to 25 minutes. This slow process brings out the onions’ natural sweetness. When done, set aside.
2. Make the Au Jus Sauce:
While the onions are cooking, pour the beef broth into a small saucepan. Stir in the Worcestershire sauce, garlic powder, onion powder, and a pinch of salt and pepper. Warm the sauce over medium heat, bringing it to a gentle simmer. Let it cook for about 5 to 7 minutes so the flavors blend nicely. Keep it warm on low heat.
3. Prepare the Rolls and Assemble the Sandwich:
Preheat your oven’s broiler. Cut each hoagie roll lengthwise, but don’t slice all the way through—leave a hinge to keep the sandwich together. Spread softened butter on the cut sides of the rolls to get a golden crust. Next, pile on lots of the roast beef, then add the caramelized onions on top. Finish with slices of provolone cheese.
4. Melt the Cheese:
Place the assembled sandwiches on a baking sheet. Put them under the broiler for 2 to 3 minutes until the cheese melts and bubbles. Keep a close eye so they don’t burn!
5. Serve and Enjoy:
Take the sandwiches out of the oven, and if you like, sprinkle some fresh chopped parsley on top. Serve each sandwich with a small bowl of the hot au jus sauce for dipping. Enjoy dipping each juicy bite into that flavorful broth—it’s the best part!
Can I Use Frozen Roast Beef for This Sandwich?
Yes, you can use frozen roast beef, but make sure to thaw it completely in the fridge overnight before assembling the sandwich. This helps keep the texture tender and ensures it heats evenly under the broiler.
Can I Make the Au Jus Ahead of Time?
Absolutely! The au jus sauce can be made a day in advance and stored in the fridge. Reheat it gently on the stove before serving, stirring occasionally to keep the flavors fresh and balanced.
How Should I Store Leftovers?
Store leftover sandwiches and au jus separately in airtight containers in the refrigerator for up to 3 days. Reheat the sandwich in the oven to keep the bread crispy, and warm the au jus on the stove before dipping.
What’s the Best Bread for French Dip Sandwiches?
Hoagie rolls or crusty French bread rolls work best because they hold their shape and absorb the au jus without getting soggy right away. Avoid very soft or thin buns that might fall apart when dipped.
