Actor reflected on the subject of food - plant-based food (10)

'plant-based food' is the definition.
(burger made from beans)

'actor reflected on the subject of food' is the wordplay.
'actor' becomes 'Bean' (Sean Bean is an actor).
'reflected' says the letters should be written in reverse.
'on the subject of' becomes 're' (re means regarding a certain topic).
'food' becomes 'grub' (grub is a kind of food).
're'+'grub'='regrub'
'regrub' written backwards gives 'burger'.
'bean'+'burger'='BEANBURGER'