Onion cut on work surface (7)

I believe the answer is:

shallow

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'surface' is the definition.
(thesaurus)

'onion cut on work' is the wordplay.
'onion' becomes 'shallot' (shallot is a kind of onion).
'cut' means to remove the last letter.
'on work' becomes 'w' (physics abbreviation. I am not sure about the 'on' bit.).
'shallot' with its last letter taken away is 'shallo'.
'shallo'+'w'='SHALLOW'

Can you help me to learn more?

(Other definitions for shallow that I've seen before include "incapable of serious thought" , "justice" , "Insincere" , "12 [TWO DIMENSIONAL]" , "flimsy" .)

I've seen this clue in The Daily Express.

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