Amphibian immersed in beef tea (3)
I believe the answer is:
eft
'amphibian' is the definition.
(eft is a kind of amphibian)
'immersed in beef tea' is the wordplay.
'immersed in' indicates the answer is hidden within the clue.
'EFT' can be found hidden inside 'beef tea'.
(Other definitions for eft that I've seen before include "Pond creature" , "Juvenile newt" , "Swimmer with feeble legs" , "Young newt" , "Slimy creature" .)