Open stove topping hollow pastry dish (5)
I believe the answer is:
agape
'open' is the definition.
(similar in meaning)
'stove topping hollow pastry dish' is the wordplay.
'stove' becomes 'aga' (I've seen this before).
'topping' is a charade indicator (letters next to each other).
'hollow' means to remove the middle letters (the word is hollowed out).
'pastry dish' becomes 'pie' (I've seen this before).
'pie' with its centre taken out is 'pe'.
'aga'+'pe'='AGAPE'
(Other definitions for agape that I've seen before include "showing disbelief" , "religious feast" , "love feast" , "(Of mouth) wide open" , "the love of God!" .)