Sushi regularly available in dull Chinese city (5)

'dull chinese city' is the definition.
I know nothing about this answer so I can't tell whether this works.

'sushi regularly available in' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'available' becomes 'wan' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in' means one lot of letters goes inside another.
The alternate letters of 'sushi' are 'uh'.
'uh' put within 'wan' is 'WUHAN'.

Can you help me to learn more?