Lamb etc? Tries sandwiches first (9)
I believe the answer is:
essayists
'lamb etc?' is the definition.
(I know this)
'tries sandwiches first' is the wordplay.
'tries' becomes 'essays' (essay can mean to try or attempt something).
'sandwiches' means one lot of letters goes inside another (to sandwich is to block something in).
'first' becomes 'ist' (ist resembles est).
'essays' going around 'ist' is 'ESSAYISTS'.
(Other definitions for essayists that I've seen before include "They write" , "Writers on various subjects" .)