Ali ill. Shh! Cheese mixes are this guy’s weakness (3,8,4)

I believe the answer is:

his achilles heel

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'this guy's weakness' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'ali ill shh cheese mixes' is the wordplay.
'mixes' indicates an anagram.
'ali'+'ill'+'shh'+'cheese'='aliillshhcheese'
'aliillshhcheese' anagrammed gives 'HIS ACHILLES HEEL'.

'are' acts as a link.

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I've seen this clue in the Sydney Morning Herald.

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