Relative behind unionist institute gets a taste of Japan (5)
I believe the answer is:
umami
'taste of japan' is the definition.
'umami' can be an answer for 'taste' (I've seen this before). I'm not certain of the 'of japan' bit.
'relative behind unionist institute gets a' is the wordplay.
'relative' becomes 'mm' (I can't justify this - if you can you should give a lot more credence to this answer).
'behind' says to put letters next to each other.
'unionist' becomes 'u' (abbreviation as in Democratic Unionist Party).
'institute' becomes 'i' (common abbreviation as in MIT).
'gets' means one lot of letters goes inside another (gets can mean captures or absorbs).
'mm' put after 'u' is 'umm'.
'umm'+'i'='ummi'
'ummi' going around 'a' is 'UMAMI'.
Can you help me to learn more?
(Other definitions for umami that I've seen before include "Savoury taste sensation produced by glutamates - I, a mum (anag)" , "Savoury flavour" , "Fifth flavour" , "meaty taste" , "Japanese word for pleasant savoury taste" .)