Battle of gala models (5)
I believe the answer is:
alamo
'battle' is the definition.
(famous mission and siege from the Texas revolution)
'of gala models' is the wordplay.
'of' says the answer is hidden in the clue.
'ALAMO' is hidden within 'gala models'.
(Other definitions for alamo that I've seen before include "Mexicans invested in Texas" , "Where Davy Crockett met his end" , "Texas fort, scene of famous siege by Mexican army" , "Fort in San Antonio, once famously besieged" , "Famous battle site in Texas" .)