There's a big distinction between a top sirloin and a bottom sirloin. Both cuts are from an area at the back of the cow between the short loin and the round, but the top sirloin is much more tender (it sits right next to the tenderloin). Because it’s the prime cut, top sirloin is usually labeled specifically as "top sirloin." Bottom sirloin is chewier and leaner and can appear as tri-tip, flap steak or under the general label of "sirloin steak." Food & Wine gives you dozens of sirloin recipes from all over the world.