Side with knight losing a horse pong's infusion? (5,5)

I believe the answer is:

greek salad

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'infusion?' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'side with knight losing a horse pong's' is the wordplay.
'side with' becomes 'agree' (I've seen this in another clue).
'knight' becomes 'k'.
'losing' indicates named letters should be taken away.
'horse pong' becomes 'salad' (I am not sure about this - if you are sure you should believe this answer much more).
'agree'+'k'='agreek'
'agreek' with 'a' removed is 'greek'.
'greek'+'salad'='GREEK SALAD'

Can you help me to learn more?

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

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