Cancel your dinner plans… because we’re making French Onion French Dip Sandwiches instead! Featuring tender caramelized onions, rare roast beef, and tons of gooey cheese, it’s everything you love about French onion soup, but in sandwich form. Use deli roast beef or get fancy and roast your own then slice it up, your call!
Have you ever started out making one thing… and then, by the end, you find you’ve actually created something completely different?!
That’s kind of what happened with these here sandwiches. It all started out with me making a little soup and sammie combo for our Sunday lunch. Innocent enough, right?
A few minutes into the “cooking thought process”, I decided to throw caution to the wind and smash the two together into one badass SUPER sandwich; combining the best parts of the french dip, and the french onion (soup).
And y’all. It worked! It totally and deliciously worked. One bite and we were all “miiiiiind BLOWN!”.
Right now I’ll break down why 😉
First up, the bread and beef. Very important stuff!
I definitely recommend finding the best baguette and beef (you want it thinly sliced, juicy, and rare, baby!) that’s available to you. They make a difference!
Then we add the whole “french onion spin” by piling on a thick layer of gorgeously caramelized onions… And then a little gruyere…
And then we pop the whole thing in the oven for a quickie 4 minute melt! This makes the bun cruuuunchy and the cheese melllllllty. Then all you gotta do is dip… and DEVOUR. We ate ours in 3 minutes flat, then sat in our full belly glory, just dreaming of the leftovers. Le sigh, this stud of a sandwich is definitely my new best friend….and my jeans new enemy!
More Sandwich Recipes:
- Easy Italian Meatball Sub Sandwiches
- Hot Ham, Swiss, and Jalapeño Sandwiches
- Italian Turkey Club Sandwiches

French Onion French Dip Sandwiches
Ingredients
- 1 long French baguette
- 1 and 1/2 pounds (340g) rare roast beef thinly sliced
- 3 Tablespoons (42g) unsalted butter
- 1 teaspoon fresh thyme leaves finely chopped
- 3 large yellow onions peeled and thinly sliced
- 1/2 teaspoon salt
- 1/2 teaspoon black pepper
- 1/4 teaspoon red pepper flakes
- 1/2 cup (113ml) cooking sherry
- 2 cups (454ml) beef stock
- 1/2 teaspoon cornstarch
- 1 teaspoon water
- 10 ounces Gruyere cheese grated
Instructions
- Slice the baguette into 4 pieces. Then slice each piece of baguette in half, taking care to only cut 3/4 of the way through the bread.
- Preheat the oven to 500 degrees(F).
- Divide the roast beef evenly among the bread, filling each roll with a 1/4 of the roast beef. Place each piece of baguette on top of a piece of aluminum foil, then set aside.
- In a large skillet, melt the butter over medium heat. Add the thyme and onions, stir well to coat, then cook on, stirring occasionally, for about 20 to 25 minutes, or until soft and golden in color.
- Add the crushed salt, pepper, and crushed red pepper and stir to combined. Cook for 2 minutes, then stir in the sherry. Cook for 3 to 4 minutes, stirring occasionally, or until the onions have soaked up the sherry.
- Add the beef stock and increase the heat to medium-high. Allow the mixture to come to a boil, then reduce the heat to a simmer and cook for another 5 minutes.
- Mix the cornstarch with a teaspoon of water to form a slurry, then add it to the onion mixture. Cook for another minute or two, allowing the “au jus” to thicken up just a bit.
- With the heat still on simmer, use a slotted spoon to scoop the onions out of the broth, and place them in a large serving bowl. Divide the au jus into individual ramekins for dipping.
- Divide the onions and shredded cheese evenly on top of the sandwiches, placing the cheese on first, then the onions.
- Wrap the foil around each sandwich, place them on a baking sheet, and place the baking sheet in the oven for 5 minutes.
- Carefully remove the pan from the oven, unwrap the sandwiches, and serve at once, with au jus on the side.
These are incredible. I mean, whoa! If i made these m family would worship me!! So I am making them!
Gurl. This is off the map.
Girl, I want this for breakfast…right now! Glad you threw caution to the wind and smashed two dishes together to create this incredible sandwich. Pinning!
Love french dip sandwiches and I love how creamy the dipping sauce is!
Ahhhh…this looks so good!! I pretty much require this immediately!
These are truly amazing. I love French Dips and French Onion Soup. Perfect combo!!
Oh yum!
Love when you decide to get brave and deviate from your originally planned out meal. Looks like you’ve created a winner!
It is such a great idea to stuff a classic sandwich like this with all the onions in the land! What a perfect way to get even more onions into my mouth. 🙂
I just made French onion soup recently. I so should have made sandwiches like this with the extra caramelized onions and cheese. They look great!
*jaw drops*
just…..whoa. AMAZINGGG! My mouth is watering
Fabulous recipe! Carmelized onions make everything better!
What is your roast beef recipe, or do you use deli beef?
Hi Lisa,
I use thinly sliced roast beef (deli meat). I really like the applegate variety they sell at my local deli. I hope that helps!
I have an “I tried it” board on Pinterest with almost 200 pins. This is by far the best recipe I have ever made from Pinterest! Loved it! Thanks!
One word: AMAZING! I wanted to make my husband a meal that would cheer him up, and this had him grinning from ear to ear! Thank you! I will definitely be making this again!
Added some French thyme to the broth for a more authentic French onion soup flavor. These were amazing.