Usual answer to "Why are you simmering that bone?" (5,5)

I believe the answer is:

stock reply

I'm a little stuck... Click here to teach me more about this clue!

'why are you simmering that bone?' is the definition.
The definition suggests an adverb which matches the answer.

'usual answer' is the wordplay.
'usual' becomes 'stock' (synonyms).
'answer' becomes 'reply' (synonyms).
'stock'+'reply'='STOCK REPLY'

'to' is the link.

Can you help me to learn more?

Want a hint initially instead of a full solution? Install my app