French Onion Burgers

Juicy and loaded with savory flavor, these French onion burgers take the best of French onion soup and a classic burger and bring them together. Made with all-beef patties drenched in a rich, caramelized onion mixture, then topped with Gruyere and cheddar cheeses for delectable gooeyness, this burger recipe is an utterly mouthwatering twist on a classic!

When a burger and French onion soup get together

Here's a little secret: a classic burger is pretty hard for my hubs and me to resist.

About every two to three weeks, one (or both) of us will get a massive craving for a burger during our work week, and we'll gleefully make plans to grab one at one of our favorite spots on Saturday for lunch. And, my, oh, my do we anticipate that "burger date" with excitement!

While we typically go for a classic burger with the works—cheese, grilled or raw onions, sauce, lettuce, tomato and pickles (extra pickles for me!)—we actually really enjoy a bistro-inspired burger-with-a-twist every now and again, one packed with unique flavors.

One of our favorites to prep at home is my Korean BBQ burger with all of its delicious Asian-inspired flavor, glossy sauce, and kimchi slaw—so mouthwatering!

But wanting to go in a more onion-y, saucy and cheesy direction, I took some inspiration from my French onion meatballs recipe, and created this French onion burger loaded with all sorts of deliciousness...

We're talking all-beef patties which are seasoned and seared. Then they're smothered in a rich, beefy, caramelized onion sauce inspired by classic French onion soup. Finally, they're topped with a combo of grated Gruyere and sharp white cheddar cheese for loads of melted, cheesy goodness.

Piled high on a soft brioche bun spread with easy garlic mayo, these French onion burgers are juicy and succulent bite after bite. And, they have plenty of sauce to make a nice mess on the plate. When we're talking burgers, the messier the better!

So if you're anything like us and crave a burger with some gourmet flare (and you love French onion soup with its cheesy topping!), then this recipe deserves a special slot in your recipe collection!

My recipe for French onion burgers

In my book, a really great tasting burger begins with quality meat. And for a beef burger, I like to opt for organic and grass-fed ground beef.

Because this recipe has lots of rich, onion-y sauce and a hefty sprinkle of ooey-gooey cheese (in other words, it's not lacking in richness and fat), I go with a lean 93/7 fat ratio for the beef. Of course, you could absolutely use 80/20 or 85/15 ratio, if desired.

I keep the seasoning simple for the beef patties, using salt, pepper, a sprinkle of granulated onion, and a couple of shakes of Worcestershire sauce for depth. And to make those patties more substantial, I make each one about 6 ounces, rather than 4 ounces.

When it comes to creating that French onion flavor, I caramelize a couple of white onions in butter and olive oil. Then I add a touch of sherry towards the end (totally optional), as well as a splash of beef stock.

The French onion sauce is so mouthwatering that it's almost irresistible to just dig into with a spoon straight from the skillet, but I do my best to resist and keep it warm to spoon over the seared patties.

And to give these French onion burgers that classic cheesy topping we enjoy in French onion soup, I grate some creamy-nutty Gruyere cheese as well as sharp white cheddar to create that delectably flavorful topping Then, I add even more onion sauce over the cheese before closing with the top bun—oh, so tasty!

Here's a glance at my French onion burger recipe: (or just jump to the full recipe...)

1. To get started, I prep my French onion sauce allowing my onions to deeply caramelize and become rich and saucy. I then keep them warm.
2. Next, I season my beef and form into patties. I allow the patties to rest in the fridge, if needed.
3. Then, I prep my garlic mayo, which is an optional (but highly scrumptious!) spread.
4. I then sear off my beef patties to medium-rare doneness in my cast iron skillet (or other pan).
5. To assemble my French onion burgers, I top with a generous spoonful of the french onion mixture, then some cheese, and then cover the skillet to allow the cheese to melt over the patties from the residual heat.
6. To finish, I place the burger patty onto a toasted brioche bun spread with garlic mayo, top with another couple of spoonfuls of the French onion mixture, cover with the top bun, and enjoy with my homemade oven fries.

Recipe

French Onion Burgers

by Ingrid Beer

Print Recipe

These French onion burgers on brioche are smothered in a French onion sauce, and topped with melted Gruyere and cheddar cheese!

Category: Sandwich
Cuisine: American

Yield: Makes 4 burgers

Nutrition Info: 1200 calories (per serving, or per 1 burger, with 2 tablespoons garlic mayo)

Prep Time: 30 minutes
Cook time: 25 minutes
Total time: 55 minutes

French Onion Burgers Ingredients:

• 3 tablespoons olive oil or avocado oil
• 1 tablespoon unsalted butter
• 2 large white onions, halved and sliced
• Salt
• Black pepper
• 2 tablespoons dry sherry (optional)
• 1 teaspoon herbes de Provence
• 1 clove garlic, pressed through garlic press
• 1 ½ teaspoons flour
• ⅓ cup beef stock or broth
• ½ teaspoon fresh thyme leaves, or ¼ teaspoon dried thyme leaves
• 1 ½ pounds lean ground beef (93/7 ratio, organic and grass-fed if possible)
• 1 teaspoon granulated onion
• ½ teaspoon Worcestershire sauce
• 1 cup grated Gruyere cheese
• ½ cup grated sharp white cheddar
• 4 brioche buns, toasted or warmed

Garlic Mayo Ingredients:

• ½ cup mayonnaise
• 2 cloves garlic, pressed through garlic press
• ½ teaspoon herbes de Provence

Preparation:

1. Begin by gathering and prepping all of your French onion burger ingredients according to the ingredients list above to have ready and organized for use.
2. Prepare your French onion mixture by placing a cast iron (or other large, heavy-bottom skillet) over medium-high heat. Once hot, add in the oil and the butter, and once melted together, add in the onions (it will seem like way too many, but they will substantially cook down).
3. Add in a good pinch of salt and pepper, and cook the onions, caramelizing them until very soft and a deep golden-brown, about 15 to 20 minutes.
4. Then, pour in the sherry (if using), and allow it bubble up and reduce. Next, add in the herbes de Provence and garlic, and stir until the garlic becomes aromatic.
5. Sprinkle in the flour and stir it into the onions, then add in the beef stock or broth and the thyme leaves, and allow the onions to cook for about 1 minute to become saucy. Spoon the onions out of the skillet and set aside, keeping the French onions warm.
6. While the onions cook, prepare your burger patties by adding the meat to a large bowl, then adding in a couple of generous pinches of salt and pepper, the granulated onion, and the Worcestershire sauce. Use your hand to distribute the seasoning evenly into the meat.
7. Portion out 4 patties that are 6 ounces each (you could even make 6 patties that are 4 ounces each, if you prefer), and press them out (or gently pound out with a mallet) so they are quite a bit larger than your buns, and thin. Place onto a tray or large plate to hold.
8. Next, add the Gruyere and the cheddar cheeses to a bowl, and toss together to combine. Set aside to have ready.
9. Then, if preparing the garlic mayo, gather and prep all of your ingredients according to the ingredient list above to have ready and organized for use.
10. To make the mayo, simply mix all of the ingredients together in a bowl with a fork, and set aside to have on hand.
11. When ready to prepare your French onion burger (or burgers), preheat your cast iron skillet to medium-high, and once hot, add one or two burger patties (work in batches depending on how many you're making) and cook the patties to your desired doneness (roughly 3 to 4 minutes per side).
12. Then, turn the heat off under the skillet, and top each patty with about 1 tablespoon of the French onion mixture, then about a heaping ¼ cup of the cheese mixture. Cover the pan with a lid and allow the cheese to melt from the residual heat in the pan and burger. (Alternately, you could place the cheese-topped patties onto a baking sheet and place under the broiler in your oven for a moment or two to melt the cheese, if desired.)
13. Once the cheese is melted, add a couple more tablespoons worth of the French onion mixture over top of the melted cheese, and garnish with fresh thyme leaves (if desired). Slather some of the garlic mayo over both top and bottom brioche buns, slide on the patty, then add the top bun.
14. Enjoy the French onion burgers on their own, with a salad, or oven fries.

Tips & Tidbits for my French onion burger recipe:

• Organic, grass-fed beef for best flavor: If you can, opt for organic, grass-fed beef here. Not only is the quality better, but the flavor is superior as well, which makes these burgers next level.
• Make your patty bigger than your bun: Burger patties tend to shrink quite a bit when cooked, so I like to press (or gently pound out) the patty to be quite a bit larger than my bun, and quite thin. That way, the patty ends up fitting the bun once seared off, and the meat is perfect thickness.
• Lots of onions to create that French onion sauce: When you slice up the onions, it will seem like too much at first. But once they begin to cook down and slowly caramelize, they will melt down into the pan substantially, becoming just the right amount.
• A splash of sherry for flavor, or leave it out: Adding sherry to French onion soup is a scrumptious touch, so I like to give this French onion sauce the same treatment for authentic flavor. The alcohol in the sherry will cook off, but if you prefer not to use it, you can simply omit it (and that step).
• A combo of Gruyere and cheddar cheese: Seeing as Gruyere is the classic cheese used to top French onion soup, I'm opting for that, as it has a really terrific meltability. I'm also using a bit of sharp white cheddar for deeper, more savory flavor—it balances the Gruyere really deliciously. You can use all Gruyere, if desired, or all cheddar, if preferred. You could also swap out whole milk mozzarella here, or your own favorite highly meltable cheese.
• Make this French onion burger to order: Unless you'd like to make all four burgers at once, you can make these "to order" by making one or two burgers at a time (depending on how many you need), and keep the other prepared patties on a plate, wrapped in plastic and in the fridge, for future meals. Then, just simply re-heat the onions, toast your buns and sear your burger patty, and enjoy fresh when desired.
• What to serve with this French onion burger: I love my oven fries on the side, or sweet potato fries, or even a nice green salad for a fresh and light take.

Craving more cozy burger and sandwich recipes like this one? Check out my Korean BBQ Burger recipe, my BBQ Meatloaf Burger recipe, my Portobello Mushroom Burger recipe, my Mediterranean Salmon Burger recipe, Veggie Burger recipe, my Roast Beef Sandwich with Cheddar Sauce recipe, or even my recipe for Southwest Sloppy Joes!