Short rib is the best cut of meat for grilling. I very strongly suggest cooking your short ribs to medium-rare—about 130°F. Any cooler than that and the intramuscular fat will remain solid and waxy, rather than unctuous and juicy. Much hotter and the fat will start leaking out copiously, making your ribs tough and dry.
Note: English cut short ribs are short ribs that are cut with one long piece of bone in each one, about 2 1/2-inches wide and 6 inches long. Look for ribs with plenty of meat and a good amount of marbling.
2 pounds boneless short ribs or 4 pounds English-cut short ribs (see note)
Kosher salt and freshly ground black pepper
If using boneless short ribs, cut into four 8 ounce portions, about 2 inches wide and 6 inches long apiece. If using English-cut short ribs, use a sharp knife to remove meat from bones. Save bones for another use.
Light one chimney full of charcoal. When all the charcoal is lit and covered with gray ash, pour out and arrange the coals on one side of the charcoal grate. Set cooking grate in place, cover grill and allow to preheat for 5 minutes. Alternatively, set half the burners on a gas grill to the highest heat setting, cover, and preheat for 10 minutes. Clean and oil the grilling grate.
Season short ribs liberally with salt and pepper and place directly over coals. Cook, turning frequently, until charred on all sides and probe thermometer inserted into thickest part of steak register 125°F, 8 to 10 minutes total. Transfer to a cutting board, tent with foil, and let rest for 5 minutes.
Thinly slice short ribs against the grain and serve immediately.