Pick over cold dessert (4-3)
I believe the answer is:
choc-ice
'dessert' is the definition.
(choc-ice is a kind of dessert)
'pick over cold' is the subsidiary indication.
'pick' becomes 'choice' ('choice' can be a synonym of 'pick'**).
'over' indicates putting letters inside.
'cold' becomes 'c'.
'choice' placed around 'c' is 'chocice'.
(Other definitions for choc-ice that I've seen before include "Cold treat" , "Frozen bar" , "Frozen sweet" , "Frozen confection" , "Cold, coated confection" .)