pick over something phrasal verb ( see also ↑ pick )
to examine a group of things very carefully in order to choose the ones you want:
She was sitting at the kitchen table picking over a pile of mushrooms.
PICK OVER (SOMETHING)
Meaning of PICK OVER (SOMETHING) in English
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012