Regurgitated food next to queen, finding bun filling (6)
I believe the answer is:
burger
'regurgitated food next to queen' is the definition.
I can't judge whether this definition defines the answer.
'bun filling' is the wordplay.
'bun' becomes 'hamburger bun' (hamburger bun is a kind of bun).
'filling' means to look at the middle letters (the letters which fill the word).
The middle letters of 'hamburgerbun' are 'BURGER'.
'finding' is the link.
Can you help me to learn more?
(Other definitions for burger that I've seen before include "Fast food item" , "Flat disc of meat in a bun" , "Meat in a bun (colloq.)" , "Incongruously varied" , "Fried cake of minced beef served in a bun" .)