Favourite extract of ripe tomatoes (3)
I believe the answer is:
pet
'favourite' is the definition.
(synonyms)
'extract of ripe tomatoes' is the wordplay.
'extract of' indicates the answer is hidden within the clue (I've seen this in other clues).
'PET' is hidden within 'ripe tomatoes'.
(Other definitions for pet that I've seen before include "Favourite; fit of the sulks" , "Favourite pupil" , "Favourite or house animal" , "Caress or fondle, as with favourite" , "Tame animal kept for companionship" .)