Without any extras (2-6)
I believe the answer is:
no-frills
'without any extras' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for no-frills that I've seen before include "Absence of inessential features" , "Ordinary" , "Straightforward" , "Basic (colloq.)" , "Without any extras - fins roll (anag)" .)