Inspired by a recent Kenji Lopez-Alt YouTube post and a tremendous hankering for a burger, I tried out these scrumptious burgers this past weekend. Nothing but ground beef, onion, cheese and a hot (very, very hot) cast iron pan or griddle needed, preferably heated on an outdoor gas grill or charcoal BBQ, so as not to have the whole house wreak of onions.
Kenji uses Hawaiian sweet buns, but feel free to use a potato or Brioche bun.
This is an interesting alternative to just serving caramelized onions on top of your burger by cooking them intermingled!
Check out Kenji's 13 minute video on the full prep and cook, or just follow my basic method below
Place your cast iron skillet or griddle over high heat on an outdoor grill or BBQ, and let the pan come up to temp for at least 10 minutes.
With you hands, roll the ground beef into balls and place on a flat tray or plate with parchment paper. I make anything from a 2oz to 4oz burger. Size however you like.
On the finest mandolin setting, slice about 2oz-3oz of yellow or white onion per burger (2.5 oz for a 4oz patty). I know it seems like a lot but bear with me here.
Pat the burgers down slightly with your fingers and season well with salt and pepper.
Turn the patty over and top with all of the onion.
Using a spatula press the onion into the patty, spreading the burger out evenly, focusing on smashing the edges until they are really thin. Don't worry about overhanging onions, in fact you want to have the onion hanging over the edge of the burger so they caramelize better
Place the burgers on your very hot pan and keep the heat on high. Season the onion side with salt and pepper. Don't crowd the burgers as they will not cook as well, keeping too much of the liquid from the meat and onions from burning off and making everything really soggy (yes, I learnt the hard way)
One minute or so for the first side should suffice
Flip the burger quickly and top with cheese, the top of the bun and then the bottom of the bun (see video for deets on why he does this)
When the onion is well caramelized around the edges, slip the spatula under the burger, remove the bun bottom and slide the burger onto it. (again best demonstrated in the video)
I will add more process shots when I do this again!