Round about lunchtime, set to have food (6)

I believe the answer is:

plaice

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'food' is the definition.
(plaice is a kind of food)

I don't understand how the remainder of the clue works.

(Other definitions for plaice that I've seen before include "Flatfish, valued as food" , "The fish sounds as if it hits the spot" , "Swimmer" , "Important food fish" , "Location of the fish" .)

I've seen this clue in the Evening Standard.

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