How do you get the patties crispy if you're steaming them in foil?
The patties are smashed thin in the pan first to develop crispy, caramelized edges before being layered with cheese and onions, then wrapped. The foil steaming happens after the crust is already formed.
Can you make the caramelized onions ahead of time?
Yes. Caramelize the onions up to 2 days in advance and store them in an airtight container in the refrigerator. Reheat gently in a skillet before assembling the burger.
What type of American cheese works best?
Deli counter American cheese (ask the butcher to slice it) melts better and tastes superior to pre-packaged singles. It creates a creamier, more authentic result.
How much ground beef should each patty weigh?
With 14 oz total for two patties, divide into roughly 7 oz portions. They'll shrink slightly during cooking, yielding two thin, crispy-edged patties.
Why wrap the burger in foil?
Foil traps steam from the hot patties and melted cheese, warming the buns and softening the toppings slightly while keeping everything warm and cohesive.