Sarah, nowadays, is a dish! (5)
I believe the answer is:
salad
'dish' is the definition.
(salad is a kind of dish)
'sarah nowadays' is the wordplay.
'sarah' becomes 'sal' (Sally is a common pet form of Sarah).
'nowadays' becomes 'ad'.
'sal'+'ad'='SALAD'
'is a' acts as a link.
(Other definitions for salad that I've seen before include "Raw greens, mainly" , "Lettuce, cucumber etc" , "healthy food" , "One may well be green" , "Food dish" .)