Trim off as much fat as possible from both sides of skirt steak. Some of it is loosely attached and can be removed by hand. Otherwise, use a knife for places where it's firmly attached. Trim off as much silverskin as you can.

Marinate steak in olive oil, lime juice, brown stugar, crushed red pepper flakes, and garlic for 15–30 minutes. Preheat grill. When hot, remove steak from marinade and season with salt and pepper. Place steak on grill, cover, and cook until seared, 2–3 min. Flip steak over, cover, and cook another 2–3 min. Transfer meat to a cutting board, tent with foil, and let steak rest 5–8 minutes before slicing.

Trimming Silverskin: To remove the tough silverskin, get underneath it with the knife tip and cut a "flap." Grip the flap, then shave the silverskin away from the meat.

Slicing Steaks: Slicing these steaks against the grain makes them more tender. Be sure to really look at the steak before slicing to see how the grain runs. The grain on flank steak runs the long way, left to right-easy to cut against. But on skirt steak, the grain goes up and down. Trying to slice against it would be difficult (and the slices would be very long). It's easiest if you first cut the skirt steak in half or thirds with the grain. Then slice the portions in strips against the grain-with a very sharp knife.