Arrange endless rosti spread (4)
I believe the answer is:
sort
'arrange' is the definition.
(thesaurus)
'endless rosti spread' is the wordplay.
'endless' means to remove the last letter.
'spread' indicates an anagram.
'rosti' with its last letter removed is 'rost'.
'rost' is an anagram of 'SORT'.
(Other definitions for sort that I've seen before include "Tidy" , "Group" , "'Variety, type (4)'" , "class" , "Arrange; category" .)