Plan to open small cafe hosting espresso martini evenings (6)
I believe the answer is:
scheme
'plan' is the definition.
(I know this)
'open small cafe hosting espresso martini evenings' is the wordplay.
'open' indicates taking the first letters (take the opening letter).
The initial letters of 'small cafe hosting espresso martini evenings' is 'SCHEME'.
'to' acts as a link.
(Other definitions for scheme that I've seen before include "Plan, ruse" , "Secret plan, plot" , "Systematic of crafty plan of action" , "Systematic plan, plot" , "Plan or act secretly" .)