Portion the beef to match the tortillas. Divide the ground beef into 8 equal portions, about 2 oz each, and shape into loose, rough balls don’t compact them. Sizing the patty to the tortilla, rather than just eyeballing a “burger-sized” portion, is the detail that makes this work as a taco instead of a burger with a tortilla wrapped around it: a patty smashed too large hangs over the edges and never gets picked up by the tortilla, while one sized to roughly the tortilla’s diameter smashes into full edge-to-edge crust that the tortilla can actually fold around.
Season the beef lightly. Season each ball with a pinch of the salt and pepper before it goes in the pan you’ll add a touch more once it’s smashed and searing.
Get the pan very hot. Heat the oil in your skillet over medium-high to high heat until it’s shimmering and just barely starting to smoke.
Smash and sear. Working in batches of 2–3 at a time, place the beef balls in the hot pan and immediately press each one flat with your spatula, using firm, even pressure, until it’s thin and about the same diameter as your tortillas. Season the exposed side with a little more salt. Cook undisturbed for about 90 seconds, until deeply browned and crisp at the edges.
Flip and add cheese. Flip each patty and immediately top with a portion of shredded cheese. Cook for another 45–60 seconds, until the cheese is melted and the second side is browned.
Warm the tortillas in the same pan. Once all the patties are done, wipe out the skillet and warm the tortillas for about 20 seconds per side, just until soft and lightly toasted with a few golden spots. Pro tip: if you want extra-crispy edges, warm the tortilla directly under the cheese-topped patty for the last 30 seconds of cooking instead of warming it separately the cheese fuses right onto the tortilla as it crisps.
Assemble the tacos. Place a smashed patty in each tortilla and add your toppings of choice diced onion and cilantro keep it close to a classic smash burger flavor, while salsa and jalapeños push it further into taco territory.
