Soften meat with care when cooking (8)
I believe the answer is:
macerate
'soften' is the definition.
(I know that macerate is a type of soften)
'meat with care when cooking' is the wordplay.
'with' says to put letters next to each other.
'when cooking' is an anagram indicator (letters cooked up into a new form).
'meat'+'care'='meatcare'
'meatcare' is an anagram of 'MACERATE'.
(Other definitions for macerate that I've seen before include "Soak" , "Steep in liquid like cream tea" , "Cream tea (anag) -- soften by steeping in liquid" , "Soften food by soaking" .)