These French Onion Beef Sloppy Joes are a fun twist on the classic! Filled with savory beef, sweet onions, and topped with ooey-gooey cheese, they are super tasty and comforting.
Who can resist melty cheese dripping down their hands? 🙈 I often pile mine high on toasted buns and add a side of fries for the ultimate lunch or dinner treat. Yum!
Making these is easy! Just cook the beef with onions, add some spices, and layer on that cheese. You can have a warm, cheesy meal ready in no time!
Key Ingredients & Substitutions
Ground Beef: Lean ground beef gives these Sloppy Joes great flavor. You can swap it with ground turkey or chicken for a leaner option. Just keep an eye on cooking times as they may vary.
Onions: Yellow onions are perfect for caramelizing, bringing out a lovely sweetness. If you’re in a pinch, white onions or even shallots can work too, but they may have a different flavor profile.
Cheese: Gruyère offers a rich, melty goodness, but feel free to substitute with mozzarella or cheddar if you prefer. Each cheese brings its own unique taste!
Worcestershire Sauce: This adds depth to the flavor. Can’t find it? A mix of soy sauce (which you already have!) and a splash of vinegar can work in a pinch.
What’s the Best Way to Caramelize Onions?
Caramelizing onions is key for that rich, sweet flavor. Here’s how to get it just right:
- Heat your skillet to medium. Add the butter for flavor and then toss in the sliced onions.
- Cook them slowly, stirring every few minutes. This process takes about 20-25 minutes. Patience is key! If they start to stick, lower the heat.
- Keep an eye on them until they’re golden brown – that’s when the magic happens! This sweetness enhances your Sloppy Joes like nothing else.
Enjoy making these delicious French Onion Beef Sloppy Joes—they’re bound to be a hit!

French Onion Beef Sloppy Joes With Gooey Cheese
Ingredients You’ll Need:
For the Sloppy Joe Filling:
- 1 lb (450 g) ground beef
- 2 large yellow onions, thinly sliced
- 2 tbsp unsalted butter
- 2 cloves garlic, minced
- 1 tbsp all-purpose flour
- 1 cup beef broth
- 2 tbsp Worcestershire sauce
- 1 tbsp soy sauce
- 1 tsp dried thyme
- 1 tsp Dijon mustard
- 1 tbsp brown sugar
- Salt and pepper, to taste
For Serving:
- 4 sandwich buns, toasted
- 4 slices Gruyère or Swiss cheese (or any melty cheese)
- Fresh parsley, chopped (for garnish, optional)
How Much Time Will You Need?
This recipe takes about 35-40 minutes altogether. You’ll spend around 10-15 minutes prepping and cooking the beef and onions, plus an additional 5-10 minutes for assembling and broiling the cheese, making it a quick and satisfying meal!
Step-by-Step Instructions:
1. Caramelize the Onions:
In a large skillet, melt the butter over medium heat. Add the sliced onions and cook, stirring occasionally, until they are golden brown and caramelized. This should take about 20-25 minutes. The slow cooking helps bring out their natural sweetness!
2. Add Garlic and Beef:
Once the onions are caramelized, add the minced garlic and stir, cooking for about 1 minute until fragrant. Then, push the onions to one side of the skillet and add the ground beef. Break it up with a spoon and cook until it’s browned and no longer pink, approximately 5-7 minutes.
3. Create the Sloppy Joe Sauce:
Sprinkle the flour over the beef and onions, stirring everything together. Cook for 1-2 minutes to cook off the raw flour taste. Gradually pour in the beef broth, Worcestershire sauce, soy sauce, thyme, Dijon mustard, and brown sugar. Stir well and bring the mixture to a simmer.
4. Thicken the Filling:
Reduce the heat to low and let the mixture simmer until it thickens, about 5 minutes. Make sure to season with salt and pepper to taste. This is where all the flavors come together!
5. Preheat the Broiler:
While the filling simmers, preheat your oven broiler.
6. Assemble the Sloppy Joes:
Scoop the sloppy joe mixture onto the bottom halves of the toasted sandwich buns. Place a slice of cheese on top of each portion of the filling.
7. Melt the Cheese:
Carefully place the assembled buns under the broiler just until the cheese melts and becomes gooey, about 1-2 minutes. Keep a close watch to prevent burning!
8. Serve and Enjoy:
Top with the bun halves, garnish with fresh parsley if desired, and serve immediately. Enjoy your delicious French Onion Beef Sloppy Joes with gooey melted cheese!

Frequently Asked Questions (FAQ)
Can I Use Turkey or Chicken Instead of Beef?
Absolutely! Ground turkey or chicken can be used as leaner alternatives. Just keep in mind that the flavor profile will change slightly, and you may need to adjust cooking times as they can cook quicker than beef.
How Do I Store Leftover Sloppy Joes?
Store any leftover filling in an airtight container in the refrigerator for up to 3 days. Reheat it in a skillet or microwave before serving on fresh buns. If you want to keep the buns crisp, store them separately.
Can I Make This Recipe Ahead of Time?
Yes! You can prepare the beef mixture a day ahead and reheat it when you’re ready to serve. Just be sure to store it in the refrigerator in an airtight container, and assemble the sandwiches just before broiling to melt the cheese.
What Can I Substitute for Gruyère Cheese?
If Gruyère isn’t available, feel free to use Swiss, mozzarella, or even cheddar cheese. Each type will provide a slightly different flavor and melt texture, so pick your favorite!