Prime cut of beef (7)
I believe the answer is:
sirloin
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">prime cut of beef</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sirloin that I've seen before include "(Knighted?) cut of meat" , "Prime cut of beef" , "Upper part of loin of beef" , "Good cut of beef" , "Joint of beef" .)