Rump cap (AUS/UK) · Coulotte · Sirloin cap — from the Sirloin primal.
The crown jewel of Brazilian churrasco: the cap muscle of the sirloin with its signature layer of clean white fat left on. Grilled fat-side toward the fire, the cap bastes the meat as it renders — huge flavor from a modest-cost cut.
What It's Called
United States: Coulotte, Sirloin cap, Top sirloin cap
Specify cap weight and fat thickness (¼–½ inch is ideal). Smaller caps eat more tender — over ~4 lb usually means the cap has grown into tougher territory.