Pat the meat dry. Rub it with oil, salt, and pepper, then let it stand at room temperature while the grill heats.
Build a hot two-zone charcoal fire. Grill the meat over direct heat until browned and lightly charred, then move it to the cooler side and cook until tender and the center reaches your preferred doneness.
Make Kachumbari and Serve:
Toss the tomatoes, onion, jalapeno, cilantro, lime juice, and salt in a bowl. Let the salad stand for 10 minutes.
Rest the meat for 10 to 20 minutes, slice across the grain, and serve with the kachumbari and lime wedges.
Notes
A meat thermometer is useful because different cuts and grill temperatures cook at different speeds.
For a more traditional presentation, grill bone-in pieces and let guests cut their own portions.