Easy French onion meatball sub sandwiches breath new life into a hohum bag of frozen meatballs and your lunch (or dinner!). Meatballs are lovingly cooked in a French onion soup bath, added to a crusty baguette, and topped with creamy Swiss cheese and caramelized onions before being baked to cheesy, delicious perfection.

A meatball can be so much more than a vessel for tomato sauce or a spaghetti topping!

We often make a double batch of Easy Baked Meatballs and almost always have some in our freezer.

And if we don’t have those, you can bet we have a big bag of store-bought frozen meatballs on hand.

Why?

Because they are so full of possibilities.

I love getting creative and tossing them with a sweet heat buffalo honey sauce for an easy appetizer everyone or making a sweet Hawaiian version that makes an incredible dinner when served over a bed of white rice.

And for a fun surprise I’ve even thrown them into quesadillas.

So naturally French onion meatball sub sandwiches surprised no one in my family.

The only surprise was how perfectly delicious this variation turned out to be!

But then again, what’s not to love about meat, caramelized onions, and tons of cheese on a toasty baguette?

Ingredients

To make these you’ll need:

Meatballs– Either frozen meatballs you’ve thawed or a batch of homemade meatballs. And it doesn’t matter if you use beef meatballs or chicken or turkey.
French onion soup– The Condensed kind found in cans.
Onions– 2 yellow onions, thinly sliced. I don’t recommend trying to sub another kind of onion, because other’s just don’t cook up the same and caramelize properly.
Butter
Cheese– We use Swiss, but provolone would also be delicious. You can use sliced (recommended), but shredded cheese will also work.
Baguettes– Crusty, good quality 6″ baguettes.

How to Make

To make these French onion meatball sub sandwiches, start by cooking the meatballs.

To do it, spread the meatballs out in a 9×13″ baking dish and pour the soup out over the meatballs and stir everything so the soup coats the meatballs.

Bake the meatballs at 350 degrees for 20-25 minutes.

Once you’ve got the meatballs in the oven, melt 2 tablespoons of butter in a medium skillet over medium heat.

Stir in the onions, and then cook, stirring often to prevent burning, until the onions are caramelized.

Remove the onions from the heat, and set aside.

Then slice the baguettes in half, if they aren’t already, and spread the rest of the butter evenly out over the insides.

Put them on a baking sheet, butter sides up.

When the meatballs are done, turn the oven to broil and put the bread in the oven.

Keep a close eye on it and broil it just until the butter melts and they’ve begun turning golden brown.

Then assemble the sandwiches by using a slotted spoon to add the meatballs to the bottom of each baguette.

Top each generously with the caramelized onions and cheese.

Broil them just until the cheese is melted and bubbly.

Remove them from the oven.

Serve and enjoy!

Storing Leftovers

I don’t recommend planning for leftover sandwiches as they will get soggy in the fridge.

However, if you know you aren’t feeding a crowd, make the French onion meatballs as directed and store any leftover meatballs in an airtight container in the fridge for up to 4 days.

Tips and Tricks

You can use any variety of meatball you have on hand or prefer.
Make sure you are stirring the onions almost constantly when you are cooking them. Stirring prevents them from sticking and burning.
Keep a very close eye on everything when you are broiling it. The bread will go from golden perfection to burnt very quickly. The same with the assembled sandwiches.

Other Meatball Recipes

French onion meatball sub sandwiches are a delicious variation on a classic meatball sub.

Make them and enjoy!

Looking for other meatball recipes?

Try these:

If you’ve tried these FRENCH ONION MEATBALL SUB SANDWICHES, or any other recipe on my site, let me know in the comment section how it turned out, we love hearing from our readers! You can also follow along with me on PINTEREST, FACEBOOK, and INSTAGRAM to see more amazing recipes and whatever else we’ve got going on!

French Onion Meatball Sub Sandwiches

5 from 2 votes

Print Pin Rate

Course: Dinner, Entree, Lunch, Main Course, Sandwich

Cuisine: American

Prep Time: 10

Cook Time: 30

Total Time: 40

Servings:

Calories: 383kcal

Author: Meaghan @ 4 Sons R Us

Ingredients

1 bag frozen meatballs thawed
1-2 10.5 oz cans condensed French onion soup
2 medium yellow onions thinly sliced
4 tbsp butter divided
12 slices thinly sliced Swiss cheese
6 6" crusty baguettes

US Customary - Metric

Instructions

Spread the meatballs out in a 9x13" baking dish. Pour the soup out over the meatballs. Stir a bit to evenly coat the meatballs.
1 bag frozen meatballs, 1-2 10.5 oz cans condensed French onion soup
Bake the meatballs at 350 degrees for 20-25 minutes.
In a medium sized skillet, over medium heat, melt 2 tablespoons of butter. Stir in the onions, and then cook, stirring often to prevent burning, until the onions are caramelized- about 7-10 minutes. Remove from heat, and set aside.
4 tbsp butter, 2 medium yellow onions
Slice the baguettes in half, if they aren't already, and spread the rest of the butter evenly out over the insides. Transfer them to a baking sheet, butter sides up.
6 6" crusty baguettes
When the meatballs are done, turn the oven to broil. Place the bread in the oven, watching closely, and cook just until the butters melted and they've begun turning golden brown.
Using a slotted spoon, add meatballs to the bottom of each baguette. Top each generously with the caramelized onions and cheese. Place them back under the broiler, just until the cheese is melted & bubbly.
12 slices thinly sliced Swiss cheese
Remove them from the oven. Top each sandwich with its top bun, and serve immediately.

Notes

You can use any variety of meatball you have on hand or prefer.
Make sure you are stirring the onions almost constantly when you are cooking them. Stirring prevents them from sticking and burning.
Keep a very close eye on everything when you are broiling it. The bread will go from golden perfection to burnt very quickly. The same with the assembled sandwiches.