Preheat the pellet grill to 225 degrees F.
Pat the sirloin cap dry with a paper towel then score the fat cap by using a sharp knife and making slits one inch apart in both directions creating a diamond pattern on the fat cap.
in a small bowl or jar combine kosher salt, black pepper, granulated onion, granulated garlic, and ground cumin.
Brush the sirloin cap on all sides with 1 tablespoon of avocado oil then liberally season the sirloin cap with seasoning blend.
Once the grill is up to temperature place the beef roast on the grill fat cap side up. Cook for about 90 minutes to 2 hours until the roast reaches an internal temperature of 120 degrees F.
At this point you have two options you can either sear the roast in a cast-iron skillet for about 2-3 minutes per side until you develop a crust or Sear the picanha on a grill over high heat around 500 degrees F. on all sides.
Once Sirloin is seared let the meat rest for 5-10 minutes then slice thinly against the grain.