Combine all the seasoning ingredients in a bowl. Coat the tri-tip with the rub and place in the refrigerator for 1 hour.
Preheat grill over low heat.
both sides of the beef on the grill
, then cook over low heat for about 30 minutes constantly turning or until internal temperature reaches 130 degrees F on an instant-read thermometer. Remove from grill to a cutting board and let rest for 10 minutes. Thinly slice and serve.