The Oklahoma Onion SmashBurger

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The Oklahoma Onion Smash Burger (Crispy & Juicy!)

The air is thick with the sound of sizzle. It’s the sound of my griddle on a Saturday afternoon, the undeniable herald of what is, in my humble opinion, one of the greatest burger experiences ever created: The Oklahoma Onion Smash Burger. This isn’t just a burger; it’s a piece of culinary folklore. Legend has it that during the Depression, resourceful cooks in Oklahoma would smash onions into their thin patties to stretch the meat and add incredible flavor. One bite of this masterpiece—with its crispy, lacy edges, the deeply caramelized, almost jammy onions fused into the beef, and the melty cheese—and you’ll understand why this tradition deserves a permanent spot in your recipe rotation.

Why You’ll Love This Oklahoma Onion Smash Burger

Pure, Unadulterated Flavor: The technique of smashing the onions directly into the patty creates a magical caramelization that makes the beef taste profoundly richer.
Textural Heaven: It’s the perfect contrast of a super crispy, crunchy sear on the outside against a tender, juicy interior.
Surprisingly Simple: With no fancy equipment needed (a cast-iron skillet works perfectly), this gourmet-style burger comes together faster than you’d think.
The Ultimate Crowd-Pleaser: This is the burger you make to impress. It’s a story and a meal, all in one.

I’ll never forget the time I made these for my friend’s son, a renowned picky eater whose diet seemed to consist solely of plain pasta and chicken nuggets. He watched me smash the onions into the patties with deep suspicion. But when presented with his own (slightly smaller) burger, he took a hesitant bite. Then another. And then he finished the whole thing, quietly asking if there were any more. That’s the power of this burger—it turns skeptics into believers.

What Makes It Special

The Onion Technique: Thinly sliced onions are salted to draw out moisture, then smashed into the patty. They steam and caramelize simultaneously, becoming sweet and tender while flavoring the beef from within.
The 80/20 Beef: This higher fat content is non-negotiable. It’s the key to achieving that crispy, flavorful crust without the burger drying out.
The Smash: Smashing the burger ball creates maximum surface area contact with the hot cooking surface, which is the secret to that irresistible, crispy-edged texture.
The Steamed Bun: Briefly steaming the bun under a lid makes it soft, warm, and pillowy, creating the perfect vessel that won’t fall apart under the juicy burger.

Making It Happen

First, let’s prep our star ingredient. Grab your mandoline (carefully, please!) and slice two large onions paper-thin. Toss them in a bowl with a good pinch of kosher salt and let them sit for about 20 minutes. You’ll see them start to sweat. This is a good thing! After their rest, take handfuls of the onions and firmly squeeze out all the excess water. This step is crucial for getting them to caramelize instead of steam.

While the onions are resting, divide your ground beef into four equal portions (about 6 ounces each) and gently roll them into loose balls. Pop them in the fridge to stay cold. A cold burger ball smashes much better.

Now, fire up your griddle or a large cast-iron skillet over high heat. Let it get properly, fiercely hot. You want to hear that sizzle the instant the meat touches the surface. As it heats, whisk together the simple burger sauce: mayo, ketchup, yellow mustard, sweet relish, a kick of hot sauce, pepper, and salt.

Time for the main event. Place your beef balls on the scorching hot surface and immediately top each one with a generous handful of your squeezed onions. Don’t be shy! Now, take a strong, flat spatula and press down hard on each one. Really put your weight into it to smash them as thin as you can. Season the tops generously with salt and pepper. Let them cook undisturbed for a solid 3-4 minutes—this is what builds that gorgeous golden crust.

Use a sharp-edged spatula to scrape and flip each patty (onions and all). They should release easily if you’ve got a good crust. Season the other side and cook for about 2 more minutes. Lay a slice of American cheese on each patty—its perfect meltability is key here. To melt the cheese and warm the buns, place the top bun on the cheese and the bottom bun upside-down on top of that. Add a few drops of water to the griddle and carefully cover the burgers with a metal bowl or pot lid for just 30 seconds to steam.

To assemble, slather the bottom bun with that tangy, creamy burger sauce and layer on some pickles. Carefully place one (or double-stack two!) of those cheesy, onion-laced patties on top, crown it with the steamed top bun, and prepare for a flavor explosion.

You Must Know

Squeeze Those Onions: Removing the water is the difference between steamed, soggy onions and caramelized, flavorful ones.
Smash It Thin: Don’t be gentle. A good, hard smash creates more surface area for the Maillard reaction (a.k.a. flavor!).
Don’t Touch It: After you smash, walk away. Let the crust form without poking or prodding.
Use American Cheese: Its emulsifiers make it melt into a creamy, velvety blanket unlike any other cheese.

Serving Ideas

Serve these burgers straight off the griddle with a side of crispy seasoned fries or tater tots for the ultimate classic experience. A simple, cooling side salad helps cut through the richness. For a drink pairing, you can’t go wrong with an ice-cold lager or pilsner. A root beer float is also a fantastic, nostalgic choice.

Make It Different

Gluten-Free: Use your favorite gluten-free buns and ensure all sauce ingredients are certified GF.
Spicy Kick: Add sliced jalapeños to the onions before smashing, or use a spicy hot sauce in the burger sauce.
Different Cheese: While American is classic, provolone or a sharp cheddar would also work well.
The Bun: Brioche is buttery and delicious, but potato buns or classic sesame seed buns are also excellent choices.

Storage and Reheating Recipe Tips

These burgers are best enjoyed immediately. If you have leftover patties, store them in an airtight container in the refrigerator for up to 2 days. The best way to reheat them is in a air fryer or toaster oven at 375°F (190°C) for a few minutes to re-crisp the edges. Microwaving will make them soft.

Success Tips

Ensure your cooking surface is screaming hot before you add the meat. A cold surface will steam the burgers instead of searing them. Use a sturdy, flat spatula for the best smash—a fish spatula is ideal for getting under the crispy patty to flip it. Work in batches if your skillet or griddle isn’t large enough to avoid overcrowding, which lowers the temperature.

Frequently Asked Questions (FAQ)

Q: I don’t have a griddle. Can I still make this?
A: Absolutely! A heavy-duty cast-iron skillet is the perfect tool for the job. Just make sure it’s preheated properly.

Q: Why is my burger sticking to the pan?
A: It’s likely not hot enough. Wait until your surface is very hot, and ensure you’re using a good amount of pressure to create a good sear that will naturally release. Also, don’t try to move it too early.

Q: Can I use a different type of onion?
A: Yellow onions are standard for their strong, sweet flavor when cooked. White onions would be a fine substitute. I’d avoid red onions as their flavor is a bit too sharp for this application.

Q: What’s the purpose of salting the onions first?
A: Salting draws out the excess moisture. If you skip this step, the onions will release too much water while cooking and steam the burger instead of allowing it to sear and crisp up.

Q: Can I make the sauce ahead of time?
A: Definitely! The burger sauce can be made up to a week in advance and stored in an airtight container in the refrigerator. The flavors actually meld and get better over time.

Prep time: 25 minutes
Cook time: 10 minutes
Total time: 35 minutes
Category: Main Course
Difficulty: Easy
Cuisine: American
Yield: 4 burgers

Ingredients

1.5 pounds ground beef (80/20 blend)
2 large yellow onions, sliced very thin
1 tbsp kosher salt (for onions)
4-8 slices American cheese
4 Brioche buns
Sliced dill pickles
Additional salt and pepper for seasoning

For the Burger Sauce:

1/2 cup mayonnaise
3 tablespoons ketchup
2 tablespoons yellow mustard
1.5 tablespoons sweet pickle relish
1.5 tablespoons hot sauce (e.g., Frank’s RedHot)
1 teaspoon black pepper
1 teaspoon kosher salt

Instructions

Using a mandoline, slice the onions very thin. Place in a bowl, toss with 1 tbsp kosher salt, and set aside for 20 minutes. After, squeeze the onions firmly to remove all excess liquid.
Divide beef into 4 equal portions (roughly 6 oz each) and gently roll into balls. refrigerate for 15 minutes.
Preheat a griddle or large cast-iron skillet over high heat.
Make the sauce by whisking all sauce ingredients together in a small bowl. Set aside.
Place the beef balls on the hot griddle. Immediately top each one with a large handful of the squeezed onions.
Using a sturdy, flat spatula, press down firmly on each ball to smash it into a very thin patty. Season the tops with salt and pepper.
Cook for 3-4 minutes without moving, until a deep brown crust forms. Scrape under the patty and flip.
Season the second side and cook for 2 minutes. Place 1-2 slices of cheese on each patty.
To steam the buns and melt the cheese, place the top bun on the cheese and the bottom bun upside-down on top of that. Add a splash of water to the griddle and carefully cover the burgers with a lid or metal bowl for 30 seconds.
To assemble, spread burger sauce on the bottom bun. Add pickles, then one or two patties. Top with the steamed top bun and serve immediately.