Trim the silver skin from the meat side of the sirloin cap.
Heat the grill to medium high.
Lightly season the picanha on all sides with Brisket Rub.
Place the whole picanha on the grill fat side down. Grill for 3-4 minutes to sear, moving it around if you have flare ups.
Flip. Grill for another 3-4 minutes.
Remove from the grill. Slice with the grain into 3 two-inch thick steaks.
Prepare the grill for rotisserie cooking with medium-high heat.
Bend each steak into a C-shape and thread onto a rotisserie spit.
Sprinkle both sides with the Gaucho Steak Seasoning.
Grill on the rotisserie until the internal temperature reaches 130F degrees, 30-40 minutes.
Let rest 10 minutes. Remove from the spit and slice against the grain.
Season with flake sea salt.