Smashburger with Onions

Today we’re making what might be the best smashburger ever! My double smashburger with onions recipe calls for two 1/3-pound organic beef patties, which I sear in a mixture of bacon grease and mustard. We’re topping them with gooey melted American cheese and sweet, caramelized grilled onions and serving it on a toasted brioche bun!

Photo of a smashburger with grilled onions

The Smashburger name is pretty self explanatory. It describes the cooking process of smashing the burgers on a flat grill, which sears in the juices and all that delicious flavor.

Smashing the burgers after searing on both sides squeezes out those tasty juices!

How to Make Smashburgers

To begin these awesome smashburgers on the griddle, we’re going to need two 1/3-pound balls of ground beef per serving.

I’m using 85 percent lean, 15 percent fat organic ground beef. This is a very flavorful beef that I buy from Costco, and it’s perfect for this recipe.

Our first step is to slice the onion into thin slivers with your chef’s knife. This is a super decadent smashburger, so we are going to slice one whole onion per serving!

Next, we’re going to caramelize the onions in about 1 tablespoon of bacon grease on a flat top grill. You can also use butter or oil. It takes a good 20-30 minutes until the onions char and caramelize.

Grilled caramelized onions are key to this double smashburger recipe.

Remove the onions to a bowl, and add your smashburgers to the grill. I like to sear them on both sides, and then give them a good smash-smash-smash with my large grilling spatula. You can also use the back of a small saute pan. 

After drizzling the mustard on the seared smash burger, flip it to seal in the flavor!

Season the burgers with a little salt and pepper on both sides. Next add your desired amount of mustard to both sides of the patties and flip to seal in the flavor.

Looks at that mustardy goodnesss!

Finally, add two slices of American cheese to each patty and close the grill to allow the cheese to melt. Next, toast your brioche bun on the griddle.

Build your sandwich with plenty of grilled onions, melted American cheese and those delicious mustard scraps from the grill!

Building Your Smashburgers

When the smash burgers are at your desired doneness, build your sandwich. I start with the burger, add a little bit of the mustard drippings from the pan, add some grilled onions, top with the second burger, more onions, and then add the toasted brioche bun on top.

Photo of the Best Smashburger Recipe - double patties with melted American cheese and grilled onions.
My double smashburger with onions calls for two 1/3-pound organic beef patties, which I sear in bacon grease and mustard.

Watch my Smashburger with Grilled Onions Video

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Photo of a smashburger with grilled onions

Double Smashburgers with Grilled Onions

Recipe by Jason Hill – CookingSessions.com
Today we're making the best smashburger recipe ever! My double patty smashburgers are seared in bacon grease and mustard, then topped with melted American cheese, caramelized grilled onions, and served on a toasted buttery brioche bun!
5 from 6 votes
Prep Time 15 minutes
Cook Time 35 minutes
Total Time 50 minutes
Course Main Course
Cuisine American
Servings 1

Ingredients
  

  • 1 brioche bun
  • 1 white onion cut into slivers
  • 1 tablespoon bacon grease or oil
  • 2 1/3-pound Angus beef patties (I used 85 percent lean, 15 percent fat organic ground beef)
  • 4 slices premium American cheese
  • Salt and pepper to taste
  • Yellow mustard to your taste

Instructions
 

  • Form your ground beef into two 1/3-pound balls.
  • Slice the onion into thin slivers.
  • On your flat top grill, caramelize the onions in about 1 tablespoon of bacon grease or oil. It’s going to take a good 20-30 minutes until the onions are charred and caramelized.
  • Remove the onions to a bowl, and add your burgers to the grill. Sear the balls on both sides, then after a few minutes, give them a good smash with a large grilling spatula.
  • Season the burgers with a little salt and pepper on both sides.
  • Next add your desired amount of mustard to both sides of the patties and flip to seal in the flavor.
  • Finally, add two slices of American cheese to each patty and close the grill to allow the cheese to melt.
  • Toast your brioche bun on the griddle.
  • When the smash burgers are at your desired doneness, remove them to a serving plate.
  • Build your smash burger. First, add one patty to the toasted bun. Add a little bit of the mustard drippings from the pan, add some grilled onions, top with the second burger, more onions, and then the brioche on top.
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Keyword beef, burgers, grilling
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AboutJason Hill

Hi, I’m Jason Hill, host of YouTube’s “Chef Tips” series. I graduated from culinary school in 1998, and gained my experience working the lines in Southern California. I launched my cooking videos in 2007. I love sharing quick and easy recipes that get people back in the kitchen.

5 from 6 votes (6 ratings without comment)

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