Restaurant in street writer's written about (6)
I believe the answer is:
bistro
'restaurant' is the definition.
(bistro is a kind of restaurant)
'street writer's written about' is the wordplay.
'street' becomes 'st'.
'writer' becomes 'biro' (I've seen this before**).
'written about' means one lot of letters goes inside another.
'st' inserted inside 'biro' is 'BISTRO'.
'in' acts as a link.
(Other definitions for bistro that I've seen before include "Small informal French restaurant" , "A small informal restaurant from France" , "Modest restaurant" , "somewhere to eat" , "Eating place" .)