One who works at an establishment that changes hands (10)

'one who works at an establishment that changes hands' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.

'one who works at an' is the wordplay.
I cannot really see how this works, but
'one' could be 'an' (an apple is one apple) and 'an' is found within the answer.
'works' could be 'is' ('be' can be a synonym of 'work') and 'is' is present in the answer.
'an' could be 'i' (Roman numeral for one) and 'i' is located in the answer.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?