Divide each pound of ground beef into 4 equally-sized balls. This gives you a quarter pound burger, which is the perfect amount for a thin patty. (yep...just like McD's)
Line up your arsenal of cast-iron cookware so you can parallelize this operation (unless you don't mind waiting a little). Set on low heat and drizzle a little olive oil on the skillet.
Place the rounded balls onto the skillets. That glorious cacophony of sizzle will let you know you've got the right temp.
Let them sizzle for 10 seconds or so and then SMOOSH them down with a metal spatula. This step is important. Keep working them flat. Flat, I say! Flatter the better. They might stick a little to the spatula. No probs--just keep smooshing them down and work off with your finger, if need be. Use a rolling / rocking motion to flatten.
Let the patties cook for around 2 minutes on the first side. Sprinkle with some black pepper and salt. When it looks like the steam is coming up through and the patty loses much of its red, color--time to flip.
Flip them over. If sticking too much when you try and flip, let them cook slightly longer. Let cook for another 60 seconds or so and add cheese of your choice. I am a sucker for Land O' Lakes American for it's even meltability (is that a word?) Once cheese is evenly melted, transfer to a plate and cover. Prepare the next 4 patties in the same way.
Once the second batch of patties is done, take the thinly sliced onions and drop them into a skillet. Let them cook for 1 minute or so and gently push around. You don't need to completely cook them. While the onions are cooking, lightly toast your bread or buns.
Somewhere in the midst of this fury, you will want to have prepared your condiments. If not, now is a good time. Here I have sliced up some pepperoncini peppers for a little extra kick. I also ALWAYS make chipotle mayo--just add some chipotle hot sauce to mayo and blend with some pickle juice and black pepper--heaven!
Assemble your lovely creations and serve! Don't forget to top them off with your lovely sauteed onions. Be prepared for mmm's and aaah's. These Smashburgers are, of course, delectable when paired with homemade fries which I usually cook in tandem. See separate recipe.
For the Chipotle Mayo, mix about 3-4 tablespoons Hellman's Mayo, some leftover pickle juice, 1 tablespoon Cholula Chipotle Hot Sauce, and a good dose of ground black pepper