Establish one explosive t-bar? (9)

I believe the answer is:

estaminet

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'bar?' is the definition.
(I have seen 'small bar' mean 'estaminet' so perhaps 'bar' could also mean 'estaminet')

'establish one explosive t' is the wordplay.
'establish one' becomes 'esta' (I can't explain this - if you can you should believe this answer much more).
'explosive' becomes 'mine' (e.g. a landmine).
'esta'+'mine'+'t'='ESTAMINET'

Can you help me to learn more?

(Other definitions for estaminet that I've seen before include "bistro" , "eatery" , "Neat items (anag) - small bar or cafe" , "provides food and drink" , "French restaurant" .)

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

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