Her tea comes out of a steaming vessel (5)
I believe the answer is:
tessa
'her' is the definition.
'tea comes out of a steaming vessel' is the wordplay.
I cannot really see how this works, but
'tea' could be 't' (I've seen this in other clues) and 't' is found in the answer.
'a' is present in the answer.
'vessel' could be 'ss' (prefix in ship names eg SS Great Britain) and 'ss' is present in the answer.
A single letter 'e' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for tessa that I've seen before include "Girl" , "Woman" , "Dahl or Jowell" , "Girl's name; former savings account" , "Girl's name, forerunner of ISA" .)