This French Onion Burger is the ultimate comfort food burger with caramelized onions and super melty fontina cheese.
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I feel I must warn you before I begin. This burger is not for the faint of heart. It's big, very big, super beefy and it's piled high with delicious caramelized onions and lots of melty fontina cheese.
Oh, and it is awesome!
Now on to what I put in this beast of a burger.
How To Make The Onions
Prep the onions first.
I wanted them not only to be caramelized but to boast the flavors of a French Onion Soup.
Slice the onions super thin. You can do this either by hand or with a mandolin.
I heated up a pan with butter AND oil and added the onions in.
After they went through their caramelization process, I added some black pepper, Worcestershire sauce and beef broth and let them cook down a bit more, just to get all that good flavor infused the onions.
Forming The Burger Patties
While all that flavor is being incorporated into the onions I formed my patties. I used plain old ground beef (85%), about 2 pounds. I seasoned it with the same seasonings I put into the onions; black pepper, Worcestershire and beef broth. You want to form these bad boys big. I was able to get 6 huge burgers out of this.
Make sure when you form your patties that you press your thumb in the center of the patty. Placing a divot there will help prevent the burger from losing it's perfect shape while cooking. If it's not shaped nice and flat on top, you'll have a hard time getting those toppings to stay put!
Cooking The Burger
Grill your burgers to your liking. I like mine a nice pink medium. It took about 12 minutes to get these big boys cooked.
Be sure not to keep your flame up too high. After I got good grill marks and the meat released a bit from the grates, I flipped them over, reduced the heat and covered the grill.
Once the burgers were looking good, I put my fontina cheese on top and closed the top again just until it was all beautiful and melty.
Oh man, I love fontina cheese. It melts so perfectly. If you haven't tried fontina yet, this is a great reason to do so.
Check Out The Video
Looking for more burger inspiration, here you go:
Printable Recipe Card
French Onion Burger
- 1 Tablespoon olive oil
- 1 Tablespoon butter
- 3 Whole medium sized sweet onions sliced thinly
- 1 Teaspoon worcestershire sauce
- 1 Teaspoon salt
- ½ Teaspoon black pepper
- ¼ Cup beef broth
- 2 Pound ground beef 85%
- 1 Tablespoon Worcestershire sauce
- 2 Tablespoon beef broth
- ½ Teaspoon black pepper
- 6 Ounce fontina cheese sliced
- 6 hamburger buns
- Heat oil and butter in a saute pan over medium/high heat. Add onions once butter is melted. After 5 minutes, reduce heat to medium and give onions a stir. Continue to cook over medium heat, if onions seem to be leaning towards burning, turn down to medium/low. Stir occasionally but not too often. After about 1 minutes, season with salt, pepper and worcestershire sauce. Cook another 5-10 minutes until onions are soft and caramelized. Deglaze the pan with the beef broth and continue to cook until liquid is just about absorbed; approximately 5 more minutes. Set aside.
- While onions are caramelizing, in a large bowl combine beef, worcestershire sauce, beef broth and black pepper. Shape into patties. You should get about 6 BIG patties. Be sure to press your thumb in the center of each patty, creating a divot, which will result in a more evenly rounded patty after cooking.
- Heat grill to medium/high heat. Place burgers on preheated grill. Cook about 5-6 minutes until burger easily releases from grates. Flip over, reduce heat to medium to medium low, depending on how hot your grill cooks. Close cover and cook another 8-12 minutes or until desired doneness. Place cheese on each burger, close cover just until cheese melts, about 2 minutes.
- Place buns, cut side down on grill to toast - about 3 minutes.
- Create burger by placing cheeseburger on bun an top with caramelized onions.