Brew using endless steam (3)
I believe the answer is:
tea
'brew' is the definition.
(I've seen this in another clue)
'endless steam' is the wordplay.
'endless' says to take the centre.
The middle letters of 'steam' are 'TEA'.
'using' acts as a link.
(Other definitions for tea that I've seen before include "Beverage; meal" , "Strangely, one may eat this drink" , "Tisane" , "Eg, gunpowder, pekoe" , "Cha" .)