Ingredients:

2 T. minced garlic
1/4 C. coarsely chopped fresh oregano
2 T. cumin seeds, toasted in a frying pan, or 1 T. ground cumin
2 T. paprika
3 T. grainy mustard
1/4 C. olive oil
1/3 C. red wine vinegar
1 3-pound bone-in or 2 1/2-pound boneless sirloin steak, 1 1/2 inches thick*
Kosher salt and freshly ground black pepper, to taste

Method:

First light a two-level fire in your grill, putting 3/4 of the coals on one side, 1/4 on the other. When the fire dies down, the coals will be hot on one side (you can hold your hand 5 inches above the grill for 1-2 seconds) and medium on the other (you can hold your hand above the grill for 3-4 seconds).

Combine the garlic, oregano, cumin, paprika, mustard, oil and vinegar. Pat the steak dry with paper towels; sprinkle with salt and pepper, then coat generously with the spice paste.

Place steak on the grill directly over the hottest part of the fire and sear well on one side, 4-5 minutes. Turn and sear well on the other side, 4-5 minutes longer. Move steak to the cooler part of the grill and continue to cook until done to your satisfaction, about 10-12 minutes for rare. To check for doneness, cut 1/4 inch into the thickest part of the meat and take a peek; it should be slightly less well-done than you like.

Remove from grill, cover loosely with foil and let rest 5 minutes before serving. Leftovers make a fantastic sandwich; any extra spice paste can be covered, refrigerated and used later to flavor any type of simple grilled meat.