Salonga of "Miss Saigon” (3)
I believe the answer is:
lea
'salonga of miss saigon' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lea that I've seen before include "Open country" , "River of east London" , "Open arable land (poet.)" , "River flowing through London" , "Field" .)