Onion Burger

Name: Onion Burger
Prep time: 10 min
Cook time: 15 min
Total time: 25 min
Cuisine: United States
Ingredients: 1 lb (450 g) ground beef (80/20 chuck), cold; 1 large yellow onion (about 10 oz/280 g), very thinly sliced (about 2 cups); 1 tsp fine sea salt, divided; 1/2 tsp freshly ground black pepper; 4 hamburger buns, split; 2 tbsp (28 g) unsalted butter, softened; 4 slices American cheese (optional); Yellow mustard and dill pickle slices, for serving

Onion Burger Say it: UHN-yuhn BUR-ger

By the Passport Plate editors. Published November 3, 2026.

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The Oklahoma onion burger is a Depression-era smash burger from El Reno, where cooks stretched scarce beef by pressing a mountain of thinly sliced onions into each patty on a blazing griddle. The onions steam, char, and fuse into the beef, creating lacy, crispy edges and a deeply sweet, savory flavor. Served on a toasted bun with mustard and pickles, it’s a beloved roadside classic that turns humble ingredients into one of America’s great regional burgers.

Onion Burger

Pronounced UHN-yuhn BUR-ger

Serves: 4
Prep: 10 min
Cook: 15 min
Total: 25 min
Level: Easy

Also nut-free and egg-free.

Allergens: contains gluten, milk. Check labels on packaged ingredients.

Ingredients

4 servings

For the burgers

1 lb (450 g)450 g (1 lb) ground beef (80/20 chuck), cold
1 large yellow onion (about 10 oz/280 g), very thinly sliced (about 2 cups)
1 tsp fine sea salt, divided
1/2 tsp freshly ground black pepper
4 hamburger buns, split
2 tbsp (28 g)28 g (2 tbsp) unsalted butter, softened
4 slices American cheese (optional)
Yellow mustard and dill pickle slices, for serving

Method

Heat a large cast-iron griddle or heavy skillet over high heat until smoking. Meanwhile, divide the beef into 4 loose balls of 4 oz (115 g) each; do not pack. Slice the onion very thinly on a mandoline or with a sharp knife.
Lightly butter the cut sides of the buns. Toast the buns on the hot griddle (or in a separate pan) until golden, about 1 minute; set aside.
Working in batches if needed, place the beef balls on the hot griddle and season each with a pinch of salt and pepper. Immediately pile about 1/2 cup (40 g) of sliced onions on top of each ball, mounding high.
Using a sturdy spatula or burger press, smash each ball firmly, pressing the onions into the beef and flattening the patty to about 1/4 inch (6 mm) thick. Press harder than you think—you want ragged, thin edges.
Cook without moving until the edges are deeply browned, lacy, and caramelized, and the onions on top are starting to soften, 2-3 minutes. The onions will steam from the top and also char at the edges.
Carefully scrape under each patty to release all the crispy bits and flip, so the onions are now underneath. If using cheese, place a slice on each patty now.
Cook for 1-2 minutes more, until the cheese melts (if using) and the onions under the patty are browned and sweet; the beef should be just cooked through but still juicy.
Place the bottom buns on plates. Top each with a patty, onions side up. Smear the top buns with yellow mustard, add pickles, and close the burgers. Serve immediately.

Regional variants

Some cooks add cheese, while others stack two thin patties with extra onions for a double. A few add jalapeños or hot sauce for heat.

Cook's notes

Use very cold beef and a very hot surface; the contrast creates the crispy lace edge.
Slice the onions paper-thin so they cook in the same time as the thin patty.
Don't salt the beef before forming balls; salt only on the griddle right before smashing to keep the texture loose.

Serve with

Serve with crinkle-cut fries, onion rings, or a cold bottle of root beer.

Make ahead and storage

Best fresh; you can slice the onions 1 day ahead and keep refrigerated. Cooked patties reheat in a hot skillet for 1 minute per side.

Onion Burger