Fuel provider stocking reduced iron drink (8)
I believe the answer is:
espresso
'drink' is the definition.
(espresso is a kind of drink)
'fuel provider stocking reduced iron' is the wordplay.
'fuel provider' becomes 'esso' (Esso is an oil company).
'stocking' indicates putting letters inside ('stock' can mean 'carry' or 'contain').
'reduced' means to remove the last letter.
'iron' becomes 'press' (I've seen this before).
'press' with its final letter taken off is 'pres'.
'esso' going around 'pres' is 'ESPRESSO'.
(Other definitions for espresso that I've seen before include "Kind of coffee made with steam" , "Coffee-making machine" , "Italian-style coffee" , "Coffee (S, not X)" , "Strong coffee made with steam machine" .)