Bistro owner upset a TU treasurer (12)

I believe the answer is:

restaurateur

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'bistro owner' is the definition.
'restaurateur' can be an answer for 'owner' (restaurateur is a kind of owner). I am not certain of the 'bistro' bit.

'upset a tu treasurer' is the wordplay.
'upset' indicates anagramming the letters.
'a'+'tu'+'treasurer'='atutreasurer'
'atutreasurer' anagrammed gives 'RESTAURATEUR'.

Can you help me to learn more?

(Other definitions for restaurateur that I've seen before include "Person running eating house" , "One catering to diners" , "Proprietor of an eating establishment" , "Eating premises owner" , "like Oliver?" .)

I've seen this clue in The Times.

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