Heat a large cast-iron skillet over medium-high heat until it just begins to smoke, about 5 minutes.

While the pan is heating, cut the skirt steak into 4 equal portions. Pat the pieces dry with paper towels and season moderately with kosher salt.

Add the tallow to the hot pan, swirling to coat the surface, and carefully lay the steak pieces in the pan, working in batches if necessary to avoid overcrowding.

Cook the steaks undisturbed for 2 to 3 minutes, allowing a golden-brown crust to form. Flip and cook for another 2 to 3 minutes for medium-rare doneness.

Remove the steaks from the pan and let them rest for a few minutes before slicing against the grain into thin strips. Serve immediately.