Bring in shrimp or tuna sandwiches (6)
I believe the answer is:
import
'bring in' is the definition.
(I've seen this before)
'shrimp or tuna sandwiches' is the wordplay.
'sandwiches' indicates the answer is hidden within the clue (the solution is sandwiched in by the clue).
'IMPORT' is hidden within 'shrimp or tuna'.
(Other definitions for import that I've seen before include "Convey" , "Bring in; significance" , "Item from abroad" , "Implied meaning, bring from abroad" , "introduction" .)