Remarkable comic performing feature during TV show (10,5)
I believe the answer is:
commercial break
'feature during tv show' is the definition.
(a TV show might feature a commercial break)
'remarkable comic performing' is the wordplay.
'performing' indicates anagramming the letters (the letters move around or 'perform').
'remarkable'+'comic'='remarkablecomic'
'remarkablecomic' is an anagram of 'COMMERCIAL BREAK'.
(Other definitions for commercial break that I've seen before include "Series of adverts" , "One may interrupt a programme" .)