Mushy peas found in recess (4)
I believe the answer is:
apse
'recess' is the definition.
(apse is a kind of recess)
'mushy peas' is the wordplay.
'mushy' indicates an anagram (letters mushed up).
'peas' is an anagram of 'APSE'.
'found in' acts as a link.
(Other definitions for apse that I've seen before include "Church's part" , "space for altar" , "Semicircular end of a church, behind the altar" , "Peas (anag) - found in church" , "Part of a church with the altar" .)