The French Dip Sandwich Melt is a delicious twist on the classic French dip, packed with juicy sliced roast beef, melted cheese, and caramelized onions all melted together on a toasted sandwich roll. The best part is dipping each bite into that rich, flavorful beef au jus that makes the sandwich so tender and tasty.
I love making this sandwich when I want something comforting but a bit more special than your regular sandwich. The melted cheese and those perfectly caramelized onions add a nice sweetness and gooeyness that really take it over the top. I like to dip mine extra slowly to soak up every bit of that flavorful jus—it feels like a little treat every time.
This sandwich is perfect for a cozy weekend lunch or an easy dinner when you want something warm and filling without a lot of fuss. Pair it with some crispy fries or a simple salad, and you’ve got a meal that everyone at the table will enjoy. Whenever I make these, I’m always surprised by how quickly they disappear—everyone loves that melty, juicy combo!
Key Ingredients & Substitutions
Roast Beef: Thinly sliced, tender roast beef is best for this sandwich. You can use deli-style roast beef for convenience or leftover roast for richness. If you prefer, thinly sliced turkey or chicken works for a lighter version.
Swiss Cheese: This cheese melts beautifully and adds a mild, nutty flavor. Gruyère or provolone are great substitutes if you want a slightly different melt and taste.
French Baguette or Hoagie Roll: A crusty bread holds up well to dipping in the au jus. If you can’t find baguette, a sturdy sub roll or ciabatta works nicely too.
Au Jus: Beef broth is the base here, and low-sodium versions help control salt. Worcestershire sauce and garlic boost flavor. If you want a thicker dipping sauce, a splash of soy sauce or a little cornstarch slurry can help.
How Do You Make Perfectly Melted Cheese That Doesn’t Overcook?
Melted cheese is the highlight of this sandwich, but it can burn or become oily if you’re not careful. Here’s a simple way to get gooey, smooth melted cheese:
- Once sandwiches are assembled with beef and cheese, place them on a baking sheet.
- Use your oven’s broiler or set the oven to a high temperature (about 400°F).
- Keep a close eye on the sandwiches and heat for just 2-3 minutes until the cheese melts and starts to bubble.
- Remove immediately to avoid overcooking.
This quick melt keeps the cheese creamy and perfectly gooey without drying it out or browning it too much.
Equipment You’ll Need
- Baking sheet – perfect for melting the cheese evenly under the broiler.
- Medium saucepan – to simmer the au jus without burning or boiling over.
- Skillet or frying pan – ideal for caramelizing onions slowly and evenly.
- Sharp knife – helps you slice the baguette and roast beef neatly.
- Small bowl – to mix the cornstarch slurry if you want a thicker dip.
Flavor Variations & Add-Ins
- Swap Swiss cheese for provolone or mozzarella for a creamier melt and milder taste.
- Add sautéed mushrooms along with onions for added texture and earthiness.
- Use thinly sliced turkey or chicken instead of roast beef for a lighter option.
- Mix fresh thyme or rosemary into the au jus to bring a herby note to the dipping sauce.
French Dip Sandwich Melt
Ingredients You’ll Need:
For The Sandwich:
- 1 French baguette or hoagie rolls (sliced for servings)
- 1 lb thinly sliced roast beef (preferably tender, cooked)
- 8 slices Swiss cheese
- 2 tablespoons butter
- 1 medium onion, thinly sliced (optional, for caramelized onions)
- Fresh parsley, chopped (optional, for garnish)
For The Au Jus:
- 4 cups beef broth (preferably low sodium)
- 1 tablespoon Worcestershire sauce
- 1 garlic clove, minced
- 1 teaspoon soy sauce (optional, for depth)
- Salt and pepper to taste
- 1 teaspoon cornstarch mixed with 1 tablespoon water (optional, for slight thickening)
How Much Time Will You Need?
This recipe takes about 35 minutes in total. You’ll spend about 10-15 minutes simmering the au jus and optionally caramelizing onions for around 20-25 minutes. Preparing the bread and assembling the sandwiches takes about 10 minutes. Melting the cheese is quick—just 2-3 minutes under the broiler.
Step-by-Step Instructions:
1. Prepare the Au Jus:
In a saucepan, mix the beef broth, Worcestershire sauce, minced garlic, soy sauce, salt, and pepper. Bring it to a gentle simmer over medium heat for 10–15 minutes so the flavors blend well. If you want a thicker jus, add the cornstarch slurry and cook for a couple more minutes. Keep the jus warm on low heat.
2. Caramelize the Onions (Optional):
Heat 1 tablespoon butter in a skillet over medium-low heat. Add the sliced onions and cook slowly, stirring now and then, until they’re golden brown and sweet, about 20–25 minutes. Set them aside for the sandwich.
3. Prepare the Bread:
Preheat your oven to 350°F (175°C). Slice the baguette or rolls lengthwise, spread butter on each cut side, and toast them in the oven for 5–7 minutes until the bread is golden and slightly crispy.
4. Assemble the Sandwich:
On the toasted bread base, lay out the roast beef evenly. Add the caramelized onions if you have them. Top everything with the Swiss cheese slices.
5. Melt the Cheese:
Place your sandwiches on a baking sheet and put them under the broiler or in the oven for 2–3 minutes until the cheese melts nicely and starts to bubble.
6. Serve:
Remove the sandwiches from the oven, top them with the other half of the bread, slice into portions, and serve immediately. Don’t forget to dip each bite into that warm, tasty au jus. Garnish with chopped parsley if you like!
Can I Use Frozen Roast Beef for This Sandwich?
Yes! Just make sure the roast beef is fully thawed before assembling the sandwich. Thaw it overnight in the fridge or quickly in a sealed bag submerged in cold water. Pat dry if needed to avoid extra moisture.
Can I Make the Au Jus Ahead of Time?
Absolutely! The au jus can be prepared a day in advance and refrigerated. Reheat gently on the stove before serving, stirring occasionally. Add a splash of beef broth or water if it thickened too much.
How Should I Store Leftover Sandwiches?
Store any leftovers in an airtight container in the fridge for up to 2 days. Reheat the sandwich in the oven or under the broiler briefly to melt the cheese again before serving.
What Are Good Bread Alternatives for This Recipe?
If you can’t find a baguette, a sturdy sub roll, ciabatta, or even a crusty sourdough loaf work well. Just choose something that holds up nicely when dipped in the au jus without getting soggy too fast.
