Chilling shelled clam with spice? (6)

'chilling' is the definition.
Although both the answer and definition are present participle verbs, I don't see how one could define the other.

'shelled clam with spice?' is the wordplay.
'shelled' means to look at the middle letters (the outer letters or shell are removed).
'with' says to put letters next to each other.
'spice?' becomes 'zing' (I can't justify this - if you can you should give a lot more credence to this answer).
The centre of 'clam' is 'la'.
'la'+'zing'='LAZING'

Can you help me to learn more?