Season the thinly sliced beef sirloin generously with salt and black pepper on both sides.
2
Heat the lard in a large skillet or comal over medium-high heat until shimmering.
3
Add the seasoned beef sirloin to the hot skillet in a single layer, working in batches if necessary to avoid overcrowding. Sear for 1-2 minutes per side until browned, then remove the beef sirloin from the skillet and set aside.
