This Oklahoma-style smash burger is a thin beef burger cooked on a very hot pan with sliced onions pressed right into the meat. The onions steam, brown, and almost melt into the beef, which makes this different from a regular grilled burger where the onions are cooked separately or added raw at the end. I make it when I want a fast, diner-style burger at home without lighting the barbecue, especially when the pan can do all the work in a few minutes.

This recipe is based on my YouTube video, with a few adjustments since publication to make the proportions easier to reproduce at home. I tightened the sauce measurements, clarified the beef amount, and added more detail on the smashing technique because that is where people usually miss the result. The mistake to avoid is pressing the meat gently. For this burger, you need heat, pressure, and thin onions.

Oklahoma Smash Burger with Maple Mustard Burger Sauce

Why This Version Works

I make it this way because the onions are not just a topping. They are part of the cooking method. When you put thin white onions directly on top of the beef ball and smash everything into the hot pan, the meat browns underneath while the onions start softening from the steam and beef fat. Then, when you flip the patty, the onions hit the pan and caramelize.

What I look for here is a thin patty with dark browned edges, not a thick meatball in a bun. The sound should be aggressive when the beef touches the pan. If the pan is quiet, it is not hot enough. If the onions are cut too thick, they stay crunchy and raw in the middle. Thin onions are the trick.

This burger is hearty comfort food, with a good amount of protein from the beef and cheese. It is not a light salad burger, but you can balance the plate with a simple salad, fresh tomato side, or baked potato if you want something more complete.

How This Burger Is Different From Other Burgers

This recipe is not the same as a classic grilled burger. A grilled burger usually has a thicker patty and more of a barbecue flavor. This one is cooked flat and fast in a skillet, with a browned crust from direct contact with the pan.

It is also different from my homemade Whopper-style burger, which is more about a classic fast-food build with fresh toppings. This one is more onion-forward, more pan-seared, and more focused on the beef crust.

Compared with my homemade Mc Bacon burger, this recipe has no bacon and no heavy stack of toppings. The flavor comes from the beef, onions, cheese, and a maple mustard sauce that brings acidity and a little sweetness.

For another ground beef meal that goes in a completely different direction, the best homemade sloppy joes are saucy and soft, while this burger is dry-seared, thin, and crispy around the edges.

Ingredients You Need

For the beef, use ground beef with some fat. I prefer medium ground beef or something close to 80/20. Extra-lean beef can work, but it will not brown as nicely and the burger can taste dry. A smash burger needs fat to help the crust form.

The onions should be white onions, sliced very thin. A mandoline works well, but a sharp knife is fine if you take your time. If you want more detail on knife technique, this guide on how to cut an onion properly is useful for getting even slices.

For the sauce, I use mustard, tomato paste or ketchup, sherry vinegar, maple syrup, and a little oil. In the original video, the sauce is more of a blended maple mustard tomato sauce than a heavy mayonnaise sauce. I prefer to keep it sharp and slightly sweet because the burger already has beef fat and melted cheese. If you want a creamier burger sauce, you can add mayonnaise, but the version below stays closer to the video.

Step-by-Step Instructions

1. Make the Sauce

In a small bowl or blender cup, combine mustard, tomato paste or ketchup, sherry vinegar, maple syrup, neutral oil, black pepper, and a small pinch of salt.

Whisk or blend until the sauce looks smooth and slightly glossy. If using tomato paste, the sauce will be thicker and a little deeper in flavor. If using ketchup, it will be softer and sweeter. Taste it. You should get sweetness first, then acidity, then mustard at the end.

At this point, it should look like a thin burger sauce, not a thick dip. If it is too sharp, add a small touch more maple syrup. If it is too sweet, add a few drops of vinegar.

Keep it cold while preparing the burgers.

2. Slice the Onions Thin

Peel the onions and slice them as thin as possible. The slices should bend easily and almost look like little ribbons. Separate them with your fingers and keep them in a bowl.

The mistake to avoid is cutting big onion strips. Thick onions will not cook fast enough, and the burger will taste raw instead of sweet and browned.

3. Prepare the Beef

Divide the ground beef into 4 loose balls, about 5 to 6 ounces each. Do not pack them tightly. You want loose beef so it spreads easily when smashed.

I prefer to season the outside just before cooking instead of mixing salt heavily into the meat. Salt mixed too early can make ground beef tighter, almost like sausage. For a burger, I want the texture to stay loose.

If you want a double smash burger, divide the beef into 8 smaller balls instead. Two thin patties with cheese in the middle will give you more browned surface and a very diner-style result.

For seasoning basics, the guide on how to season a recipe properly is a good reference, especially if you tend to under-salt beef.

4. Heat the Pan Until Very Hot

Use a cast-iron pan, carbon-steel pan, or flat griddle if you have one. Heat it over high heat until it is very hot. You should see a little shimmer if there is oil in the pan, and the beef should sizzle hard the second it touches.

Add only a thin film of oil if your pan needs it. Too much oil makes the burger fry instead of sear.

Work in batches if your pan is small. Crowding the pan drops the heat and makes the meat steam.

5. Smash the Burgers

Place one beef ball in the hot pan. Immediately season with salt and pepper. Add a handful of sliced onions directly on top of the beef.

Press hard with a sturdy metal spatula, burger press, or the bottom of a small saucepan. Hold the pressure for about 8 to 10 seconds. The patty should become thin, wide, and uneven around the edges.

You know it is working when the edges start browning quickly and the beef smells roasted, not boiled. Do not move it around. Let the crust form.

Cook for about 1 1/2 to 2 minutes on the first side.

6. Flip Onion-Side Down

Scrape under the burger firmly with the spatula, making sure to lift the browned crust from the pan. Flip the patty so the onions are now underneath.

The onions will hiss when they hit the pan. That is good. Let them cook in the beef fat for another 1 to 2 minutes, until they soften and brown in spots. They should be caramelized, not burnt black.

Add cheese on top and cover briefly so it melts. The cheese should relax over the beef and onions, not just sit there cold.

For doneness, thin smash burgers cook fast. If you are unsure about safe cooking temperatures for ground beef, check this internal cooking temperature chart.

7. Toast the Buns

Toast the buns in a separate pan with a little butter or oil, or use the edge of the griddle if there is room. The cut side should become lightly golden and a little crisp. This helps the bun hold the sauce without getting soggy too fast.

If serving these with fries, the timing matters. I like to have the fries ready before the burgers go on because the meat cooks so quickly. These crispy McDonald’s-style fries are a natural match if you want the full fast-food plate at home.

8. Build the Burger

Spread sauce on the bottom bun. Add a little arugula or lettuce if you want freshness, but keep it light. This is not a salad sandwich.

Place the hot patty with melted cheese and onions on the bun. Add more sauce if desired, then close the burger.

Serve right away. A smash burger waits for nobody. After a few minutes, the cheese firms up, the bun softens, and the crust loses some of its magic.

Substitutions

You can use regular ground beef instead of Angus beef, but choose beef with enough fat. Medium ground beef works better than extra-lean.

White onions are best, but yellow onions also work. Red onions are stronger and less classic for this style.

Cheddar, American-style cheese, Monterey Jack, or processed burger slices all work. I like cheese that melts quickly because the patty is thin and the cooking time is short.

If you do not have sherry vinegar, use red wine vinegar or apple cider vinegar.

If you do not have maple syrup, use honey, but the flavor will be different. Maple syrup gives the sauce a more Canadian touch without making it taste like dessert.

For a creamier sauce, mix 3 tablespoons mayonnaise with 1 tablespoon mustard, 1 tablespoon ketchup, 1 teaspoon sherry vinegar, and 1 tablespoon maple syrup.

What to Serve With It

A burger like this goes well with something crisp, fresh, or potato-based. For a classic plate, serve it with crispy homemade onion rings or air fryer baked potatoes.

If you want a cold side, a scoop of classic macaroni salad works well because the creamy pasta balances the salty beef and onions. For something fresher, serve it with fresh tomato bruschetta on the side instead of loading the burger with too many toppings.

For another sandwich idea with a Canadian feel, try the Montreal club sandwich. If you want to stay in the beef category but not make burgers, the easy beef tartare recipe goes in a completely different fresh direction, while the budget steak with baked potato keeps things simple and hearty.

FAQ

Can I make this burger on the barbecue?

Not really in the same way. The whole point is the hard contact with a flat hot surface. A barbecue grate will not smash the beef properly, and the onions will fall through. Use a cast-iron griddle on the grill if you want to cook outside.

Do I need a burger press?

No, but it helps. A strong metal spatula works if it does not bend. You can also press down with another spatula on top or use the bottom of a small pot.

Why are the onions added before smashing?

Because they cook into the beef. When the burger is flipped, the onions brown in the beef fat and become part of the patty instead of sitting on top like a garnish.

Can I make the sauce ahead of time?

Yes. The sauce can be made 2 to 3 days ahead and kept in the refrigerator. Stir it before using.

Can I make this with turkey or chicken?

You can, but it becomes a different recipe. Beef works best for smash burgers because the fat helps browning. If using poultry, cook it fully and expect a less crispy crust.

Why did my burger stick to the pan?

The pan may not have been hot enough, or you tried to flip too early. Let the crust form, then scrape firmly under the patty. A thin metal spatula is better than a thick plastic one.

Oklahoma Smash Burger with Maple Mustard Burger Sauce

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Prep Time 20

Cooking Time 10

Total Time 30

Category Main Dish

Cuisine American

Portions 4 burgers

Calories 620 kcal

Ingredients

For the Burgers
1 1/2 lb medium ground beef ideally 80/20
1 large white onion sliced paper-thin
1 tsp kosher salt or to taste
1/2 tsp black pepper or to taste
4 hamburger buns
4 slices cheddar or American-style cheese
1 tbsp butter or neutral oil for toasting buns
1 cup arugula or lettuce optional
For the Maple Mustard Burger Sauce
1 tbsp mustard
1 tbsp tomato paste or ketchup
1 tbsp sherry vinegar
1 to 2 tbsp maple syrup
3 tbsp neutral oil or peanut oil
1 pinch salt
Black pepper to taste

Instructions

Mix or blend the mustard, tomato paste or ketchup, sherry vinegar, maple syrup, oil, salt, and black pepper until smooth. Refrigerate while preparing the burgers.
Slice the onion as thinly as possible and separate the pieces with your fingers.
Divide the beef into 4 loose balls. Do not pack the meat tightly.
Heat a cast-iron pan, carbon-steel pan, or griddle over high heat until very hot. Lightly oil the surface only if needed.
Place one beef ball in the hot pan. Season with salt and pepper. Add a handful of onions on top, then smash hard with a sturdy spatula or burger press until very thin.
Cook without moving for 1 1/2 to 2 minutes, until the bottom is deeply browned. Scrape under the patty and flip onion-side down.
Cook for another 1 to 2 minutes, until the onions soften and brown. Add cheese and cover briefly to melt.
Toast the buns with a little butter or oil until lightly golden.
Spread sauce on the buns, add optional arugula or lettuce, then place the hot patty with melted cheese and onions inside. Serve immediately.

Video

Notes

FAQ