The Oklahoma Onion Burger, sometimes called the “Okie burger” or a fried onion burger, is piled high with thinly sliced onions and smashed on a flat top grill or griddle. And it is dang delicious!
If you love the hamburgers from White Castle or Krystal, then you have got to try this Oklahoma Onion Burger. My wife is not a burger fan (she only likes a Burger King Whopper), but even she scarfed down a whole one by herself. She even said that next time I make burgers at home, I better make hers an onion burger.
It’s simple. It’s greasy. It’s delicious. Everything you want in a burger. Here’s how to do it:
What is an Oklahoma Onion Burger?
An Oklahoma Onion Burger is just a hamburger cooked with sliced onions. It was first developed during the depression when a few western Oklahoma restaurants started smashing sliced onions into their beef patties to help with food costs. At the time, ground beef was expensive but onions were more affordable, so the onions acted as a “filler” and helped the restaurants’ bottom line.
This burger may sound simple, but the flavor is extraordinary. The onions help to flavor the beef, and the beef fat helps to cook the fried onions, so smashing the two together really is the perfect marriage of ingredients.
What You Need to Make the BEST Oklahoma Burger
Ingredients
The ingredients for an Oklahoma Onion Burger are few and simple, making this burger a good cheap option for feeding a crowd. Here’s what you need:
- Ground beef – We used 75/25 ground beef because the extra fat helps to keep the burger moist and it also flavors the onions.
- Thinly sliced onions – We used Vidalia onions.
- Simple burger seasoning – I just used a combination salt, pepper, and garlic powder (1 TBSP salt, 1 TBSP pepper, 1/2 TBSP garlic powder).
- American cheese – Optional, but delicious!
- Hamburger buns of your choice
Cooking Tools
The fried onion burger is traditionally cooked on a flat top griddle, but you can also make it in a cast iron skillet on your stovetop, or even on a charcoal grill with a cast iron griddle set on top of the grates. I have made this onion burger 2 different ways, on my Camp Chef Flat Top Grill 600 and also on my Weber Summit Charcoal Grill with a Lodge cast iron griddle.
I personally preferred the taste of the burger on the charcoal grill with the cast iron griddle, because I felt that the combination of the grill with the cast iron got screaming hot and gave the onions a nice char. However, this fried onion burger was also freaking fantastic on the Camp Chef flat top grill. Try it both ways and see what you prefer!
Mandoline vs. Knife – Which is better for thinly sliced onions?
You have two options for slicing onions super thin: using a mandolin or slicing them by hand with a knife. I tried both methods for my onion burgers, and I was able to get thinner onion slices by hand with my vegetable cleaver. However, if your knife skills aren’t great, you can definitely use a mandoline set to the thinnest setting.
Taste wise, the thinner sliced onions that I cut by hand with a knife were better because I think they cooked down and caramelized more than the ones with the mandoline which were thicker.
*Chef’s Tip – If you don’t have a mandoline and you’re not comfortable making super thin slices by hand, then pre-cook your onions on your flat top until they’re about halfway done. Then, you can smash your ground beef balls into the sautéed onions and you don’t have to worry about the onions not cooking enough before the beef is done.
How to Make an Oklahoma Onion Burger on Your Flat Top Grill
Step 1: Preheat your flat top grill or griddle.
Turn your burners on to high and allow your flat top to heat up. No need to add any oil or butter, because there is plenty of fat in the 75/25 ground beef.
Step 2: Roll your ground beef into balls and put on the griddle.
Form your beef into 1/4 lb balls. Then, place the balls on the pre-heated flat top like this:
Be sure to space out your burger balls enough so that when you smash them down, they have plenty of room to cook and you have space to slide the spatula underneath to flip them.
Season your burger balls with a mix of salt, pepper, and garlic powder, or your favorite burger seasoning. Don’t worry about the extra seasoning getting on your flat top… it will just act as extra flavor for your onions.
Step 3: Top the beef balls with sliced onions.
Just pile your onions high on top of the beef balls. Don’t worry about the onions sliding off the beef… you can adjust when you flip your burgers.
Most people smash the ground beef with the onions on top at this stage, but I did mine a bit differently. Instead of smashing the burger with the onions on top, I flipped my burger balls and onions and smashed them with the onions on the bottom of the patty.
Why did I do it differently?
A few reasons: 1) I thought that the onions would cook better in the residual beef fat right on the flat top grill, instead of being smashed on top of the burger first. 2) Having the onions on the bottom (in between the grill surface and the ground beef) helps to act as an insulator when you smash the beef, so that the ground beef does not cook as quickly, giving the onions time to get nice and caramelized.
But if you want to go with the traditional method of smashing the burger with the onions on top, that works too.
Step 4: Flip your onion burgers and smash.
After just a couple minutes, flip your burger balls and onion slices over and smash them down together on the flat top. Leaving your burger balls on the hot grill for just a few minutes helps to release some of the fat from the ground beef, so that when you flip you’ve got a nice pool of fat for your onions to cook in.
Step 5: Top your Oklahoma Onion Burgers with cheese and steam the hamburger buns.
Once your onions are cooked, flip your smashburgers making sure that you use your spatula to get underneath the onions and all of the delicious drippings.
Then, add one slice of American cheese to each patty. I put the cheese on top of the sliced onions to help keep the onions from falling off the burger.
I also added the buns to the flat top as shown in the photo above, so that the buns could steam and soak up some of the beef fat. You’ll notice that I put the top of the bun on one patty and the bottom of the bun on another patty.
Step 6: Build your onion burger with two patties and your favorite toppings.
Since the onion burgers are thinner, I recommend doing a double patty. To easily plate your onion burgers, use your spatula to take the patty with the bottom bun and turn it upside down on your plate. Then stack the other patty and bun on top.
As far as toppings go, I would recommend just yellow mustard and pickles, similar to a White Castle hamburger. Or you could even eat it without toppings since it’s so juicy and flavorful.
If that picture doesn’t make you want to run to the grocery store right now for ground beef and onions, I don’t know what will!
If you try it, be sure to leave me a comment down below letting me know what you think! And if you want to try another awesome smash burger to make on your Camp Chef or Blackstone, check out my Taco Smashburger made with chorizo:
Want to watch me cook this onion burger? Visit my YouTube Channel! Or go ahead and print the recipe down below:
Oklahoma Onion Burger
Ingredients
- 1 lb. 75/25 ground beef
- 1/2 sweet onion
- simple burger seasoning – We used a mix of salt pepper, and garlic powder (ratio 2:2:1).
- 4 slices American cheese
- 2 hamburger buns
- yellow mustard and pickles optional
Instructions
- Preheat your flat top grill or griddle on high. If using a cast iron skillet, preheat on medium heat.
- Thinly slice the onion using a knife or mandoline on the thinnest setting.
- Roll the ground beef into 1/4 pound balls. TIP – Form the beef into a log shape, cut in half, and cut each half in half again to get approximately 1/4 pound burgers.
- Place the ground beef balls on the preheated flat top grill or in the cast iron skillet. Sprinkle seasoning on top.
- Add an equal amount of thin-sliced onions to the top of each ground beef ball.
- Allow the burger balls to cook as is for about 2 minutes to start to form a nice char on the bottom.
- After about 2 minutes, carefully flip the burger balls so that the sliced onions are now on the bottom, in contact with the flat top or cast iron skillet.
- Using two spatulas for leverage, smash the ground beef balls down into the onions. Allow the onion burgers to cook until almost done.
- Flip the onion burgers. Top each onion burger patty with one slice of American cheese.
- Place one bun half on top of each patty. This allows the bun to steam in the burger fat.
- Build your Oklahoma Onion Burger with two patties. Top with yellow mustard and pickle or your favorite burger toppings.
Video
Reader Interactions
Get More Griddle Recipes!
Follow The Flat Top King on Youtube for more recipes and tips for mastering your griddle!
Comments & Reviews
nratt30 says
This evening, I took my new Blackstone on its maiden voyage using the King’s guide for Onion Smash Burgers ( which were decidedly more NC than OK). I claim a qualified success. Never mind that I dropped the bottom bun for my wife’s burger on the ground.
Kim says
Great! Doing them in about an hour.
Chris Nichols says
Tried this based on your video and was a hit with friends and (most important) the wife. Thanks for the tons of content and I’ll be trying the Tennessee cheesesteak this weekend!
Congrats on 100K subscribers!
Patrick says
i cant wait to try this…. I’m so impressed with everything ive made for me and my family and i owe it all to you. thanks king!
Dana Canfield says
Classic and you nailed it. As a former Marine on a USN Carrier (CVN 71) I appreciate you and all the Navy cooks!
Royal Sanford Durant says
This Oklahoma Onion Burger has got to be one of the best things I’ve cooked on my griddle. Absolutely delicious.
Mike R. says
Did not disappoint, family loved it!
Paul DeVries says
Excellent recipe. I will be trying these this weekend at the camper!
Chad says
Love this one! Thanks!
Deanna M. says
This is a solid go-to favorite in our household! Must try. You won’t be disappointed.
Kevin Meilleur says
One of my most favorite burgers!!! So juicy. Your recipes are costing me calories!!! LOL
But keep them coming
Joseph Prestwood says
I believe I could eat a burger sandwich every single day of my life. Also, I require my burgers to have onions. So why not incorporate the burger & onions into one cheesy gooey mess of a sammich…..this is a home run burger….
Dave says
These burgers all look delicious, if I had a griddle, I’d try ‘‘em all!
Tom Gross says
Our favorite burger to make. We make it often.
Steve Cozzola says
This is one I really want to try I 1st saw it with George Moltz and thought it looked amazing!
Patrick Bristol Jr. says
Amazing burgers, absolute must cook on the flat top
Sam Harper says
So freaking amazing!!
Cindy says
These rock. They’re the best!
Trisha King says
we made this over the weekend for my dad. loved it.!! will be making it again and again.
Todd Alix says
My #1 go to burger.
Greg Julian says
I had only been making regular smashburgers. That is until, I learned fron the Flat Top King you can make them with onions on one side – the Oklahoma smashburger. Both are favorites og my family and when we have friends over!!! Awesome recipe!
Jason Gillespie says
Delicious love a good onion burger!
George Harvey BAT 13 says
Fantastic job with this recipe Neal! Delicious as alway ! 🍻
SCAFFIDI SCAFFIDI says
I can’t wait to get my flat-top griddle. I have cooked Oklahoma Onion Burgers on my Lodge griddle, but this looks so much better.
Patrick Lear says
This has become one of my favorite burgers! Spectacular!
Kristina says
I own a foodcart and looking to expand on my smashburger. we currently toast the buns. How do.you feel the steamed buns will hold up for ppl that are taking the onion burgers home?
Mark says
Hello, do the traditional OK Onion Burgers use dill pickles or bread and butter pickles? Thanks, Mark
Neal says
Hi Mark! I believe that it’s dill pickles, but if you’ve watched me cook on YouTube, you know what I like to say… use what you like.
Eve Mitchell says
I loved what you said about mixing the onions into the patty for a true Smashburger. I love to eat burgers, and I think there are so many options for diverse flavors with them. I’d love to go to a restaurant and try some more unique flavor burgers.