Rocky Cohen's hiding additives on bread snack from The Grill (6,2,5)

'rocky cohen's hiding additives' is the definition.
I know nothing about this answer so I cannot tell whether this works.

'on bread snack from the grill' is the wordplay.
I cannot quite understand how this works, but
'on' is within the answer.
'bread' could be 'toast' (toast is a kind of bread) and 'toast' is located in the answer.
The remaining letters 'cheese' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?