Chinese tea used in Tethys only (5)

I believe the answer is:

hyson

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

'chinese tea' is the definition.
The definition suggests a singular noun which matches the answer.

'in tethys only' is the wordplay.
'in' says the answer is hidden in the clue.
'HYSON' is hidden in the letters of 'tethys only'.

'used' acts as a link.

Can you help me to learn more?

I've seen this clue in The Hindu.

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