From Longman Dictionary of Contemporary Englishpick over something phrasal verbEXAMINEto 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→ See Verb table
Examples from the Corpus
pick over • They will certainly have plenty to pick over.• Back at the cottage she found Rodney and Veronica in the kitchen picking over a pile of fungi.• The local rubbish-tip near the roadside is constantly picked over by gulls, starlings, crows and ravens.• Sometimes we went to the Cours Mirabeau and watched the debris from the daily market being picked over by the local dogs.• These fingers holding cups and glasses are the ones you see picking over clothes on the stalls.• They had picked over discarded fruits and vegetables evenings under Park Avenue Bridge, cooking over Sterno stoves.• That's if the lawyers left her anything after they'd picked over the bones.• Crows were busy picking over the remains of a thousand improvised picnics. 