As stars might do, two minutes into shire performance (7)
I believe the answer is:
shimmer
'as stars might do two' is the definition.
I can't tell whether this defines the answer.
'minutes into shire performance' is the wordplay.
'minutes' becomes 'mm' (an abbreviation for minutes written twice).
'into' means one lot of letters goes inside another.
'performance' is an anagram indicator.
'shire' is an anagram of 'shier'.
'mm' going inside 'shier' is 'SHIMMER'.
Can you help me to learn more?
(Other definitions for shimmer that I've seen before include "Shine tremulously" , "Twinkle" , "glow" , "Glisten (on water?)" , "Gleam tremulously" .)