Step 1

Divide the ground beef into four (4-ounce) portions and roll into balls. Heat a large (12-inch) cast-iron skillet or griddle over medium-high heat until it is very hot and just barely starts to smoke. Add the oil, and tilt and swirl the skillet or griddle to distribute. Working in batches as needed, add the portions of beef to the skillet, smash with a large metal spatula as thinly as possible, lightly sprinkle with salt and pepper, and cook until browned and crisp on the bottom, about 3 minutes. Flip, top with the cheese, if using, and cook until browned on the other side and the cheese has melted, about 2 minutes. Transfer to a platter, scrape the skillet to remove any browned bits or melted cheese, and repeat with the remaining portions of beef.

Step 2

Add 1 of the cooked burgers to the bottom of each bun, followed by your favorite toppings, then cover with the bun tops. Serve hot.