They could be about spice blending (7)
I believe the answer is:
recipes
'they' is the definition.
Both the answer and definition are plural nouns.
Maybe there's a link between them I don't understand?
'about spice blending' is the wordplay.
'about' becomes 're' ('re' means regarding or about).
'blending' indicates an anagram (letters blended or mixed into a new form).
'spice' is an anagram of 'cipes'.
're'+'cipes'='RECIPES'
'could be' acts as a link.
Can you help me to learn more?
(Other definitions for recipes that I've seen before include "Directions for making dishes" , "Directions for making a dish" , "Pierces to find formulas" , "formulae" , "Directions for the cook" .)