🍔 Smash Burgers with Caramelized Onions
Ingredients
- 1.5 lb ground beef
- 4 burger buns
- Cheddar or American slices
- 2 onions
- Lettuce & tomato
- Butter
- Salt & pepper (pantry staple)
Instructions
- Slowly caramelize sliced onions in butter, 15 min.
- Smash beef balls onto a ripping-hot griddle; season, flip at a crust, add cheese.
- Stack on toasted buns with onions, lettuce, and tomato.
Tips
- Don't handle the meat more than necessary, and don't season until the balls hit the griddle. Salt mixed into raw mince dissolves the proteins and gives a springy, sausage-like texture.
- Smash once, hard, in the first 30 seconds, then leave it alone. Pressing later just squeezes out the juices you want.
- 80/20 mince, not lean. The fat is what makes a burger a burger — 90/10 gives a dry patty no technique will rescue.
Substitutions
- Ground beef
- 80/20 chuck is ideal. Lamb or turkey work, though turkey needs added fat. Plant-based patties don't smash well — cook them conventionally.
- Cheddar or American
- American melts most reliably and is the classic smash-burger choice. Cheddar, Swiss or blue all work.
- Burger buns
- Potato rolls are the standard for a reason — soft enough to compress, sturdy enough to hold. Brioche is sweeter.
- Caramelised onions
- Raw onion for sharpness, or crispy fried onions. The 15 minutes is worth it if you have the time.
Storage & reheating
Cooked patties keep 3 days but are much worse reheated — smash burgers are a cook-and-eat food. Raw portioned balls keep 2 days refrigerated or 3 months frozen. Caramelised onions keep a week and freeze well, so make extra.
Common questions
Why smash instead of a thick patty?
Smashing maximises contact with the hot surface, which maximises the Maillard crust. It's a different burger from a thick pub patty — crisp-edged rather than juicy-centred.
Do I need a cast iron pan?
It helps a great deal. You need a surface that holds heat when cold meat hits it — cast iron or carbon steel. Thin non-stick won't build the crust.
How do I stop the patty sticking to the spatula?
Put a square of parchment between the spatula and the meat when you smash, then peel it away.