Carefully select spinach cooked in stew (4,3,6)

I believe the answer is:
pick and choose
'carefully select' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'spinach cooked in stew' is the wordplay.
'in stew' indicates an anagram (I've seen this in other clues).
'spinach'+'cooked'='spinachcooked'
'spinachcooked' is an anagram of 'PICK AND CHOOSE'.
Can you help me to learn more?
(Other definitions for pick and choose that I've seen before include "Be fastidiously selective" , "Select fussily" , "Select with care" , "Be fussy" .)
