Oklahoma-Style Onion Smash Burger Recipe: Juicy, Crispy Patties

These Oklahoma-style onion smash burgers are a double-stacked, flavor-packed take on the classic smash burger. Each sandwich layers thin, caramelized sweet onions with American cheese and a tangy burger sauce that you’ll want to make again and again. The assembly is simple, but the contrast of crispy edges, juicy beef, and sweet onions delivers big taste.

Where did the Oklahoma onion burger originate?

The Oklahoma onion burger dates back to the 1920s during the Great Depression. At the Hamburger Inn, the owner began adding sliced onions to patties as a cost-saving filler. Ground beef was expensive, but onions were inexpensive and added extra flavor. The idea spread across the state and the onion burger remains a beloved regional specialty.

What are the best onions to use?

Sweet onions are the preferred choice. Their higher sugar content helps them caramelize beautifully under the beef. Avoid red onions for this preparation—they can be too sharp and compete with the beef’s flavor. Sweet onions give the mild, mellow taste that complements the patty.

The best way to cook smash burgers

A flat griddle such as a Blackstone is ideal for smash burgers because it provides a large, evenly heated surface to form a consistent crust. A heavy cast-iron pan is the next best option. The secret is high surface temperature so the patties sear instantly when smashed. If you plan to make smash burgers often, a proper burger press is worth the investment; otherwise, use a sturdy, heavy spatula.

Ingredients you need for Oklahoma-style smash burgers

How to make Oklahoma-style smash burgers

Preparing the onions

Slice the onions very thin—ideally using a mandoline for uniform, almost translucent slices. If you don’t have a mandoline, use a very sharp knife and slice as thinly and evenly as possible. Thinner slices cook faster and meld better with the beef.

Making the sauce

This burger benefits from a simple, flavorful sauce. Combine mayonnaise, ketchup, relish (or chopped pickles), yellow mustard, apple cider vinegar, Worcestershire sauce, a little sugar, and salt and pepper to taste. The sauce adds tang, sweetness, and creaminess that complements the beef and onions.

Though the ingredients are simple, the combined flavors form a balanced sauce that lifts the sandwich without overpowering the onion-beef pairing.

Forming the burgers

Divide the beef into 2–3 ounce balls for thin patties. When smashed, they’ll spread wider than the buns but will shrink slightly during cooking. After smashing, season with salt, black pepper, and garlic powder. The patties should be thin and develop a deep, flavorful crust.

Cooking the Oklahoma-style smash burgers

Heat your griddle or cast iron pan over medium-high heat. Add a little olive oil, place the beef balls on the hot surface, and press them flat with a burger press or heavy spatula. Aim for thin, even patties. Season each patty and immediately top with a handful of thinly sliced onions.

Cook for about 1–2 minutes, then carefully flip each patty so the onions are underneath, cooking in the beef fat. This method gives the onions great color and flavor as they caramelize. Let the onions cook down a few minutes, then top each patty with a slice of cheese to melt.

Once the cheese is melted, remove the patties. Toast the buns briefly on the griddle if desired, then assemble while everything is hot.

Assembling the burgers

Double-stack two patties on the bottom bun, spoon burger sauce over the top patty, and finish with the top bun. The combination of crispy edges, juicy meat, sweet caramelized onions, and tangy sauce is what makes this version so satisfying.

Because the components are simple, each element shines—try the burger as written before adding extra toppings to appreciate the balance of flavors.

Can I add additional toppings?

Of course—you can customize however you like. That said, part of this burger’s appeal is its simplicity. Extra toppings can upset the delicate balance, so try it as written first and then experiment.

Sides that go well with burgers

Homemade pasta salad

Smoked green bean casserole

Loaded baked beans

Smoked mac and cheese with bacon

Print