A spot, you say, of food (6)
I believe the answer is:
plaice
'food' is the definition.
(plaice is a kind of food)
'a spot you say' is the wordplay.
'a spot' becomes 'place' ('place' can be a synonym of 'spot').
'you say' indicates a 'sounds like' (homophone) clue.
'place' sounds like 'PLAICE'.
'of' is the link.
(Other definitions for plaice that I've seen before include "A succulent flat-fish" , "Swimmer" , "Large flatfish" , "N. Atlantic flatfish" , "Ice, pal, will catch this fish" .)