Leave it whole. Trim any silver skin off. Marinate a couple of hours in the Original Pace Hot Picante Sauce (
https://www.campbells.com/pace/products/picante/hot-picante-sauce/ ). I perforate the meat/marinade with a fork. The vinegar helps tenderize the meat. Grill over hot coals till medium rare. Slice across the grain. Layer on your favorite tortilla with a good homemade hot sauce and some guacamole.
BP...
