Food plate slyly hidden regularly by Australian (6)
I believe the answer is:
paella
'food' is the definition.
(paella is a kind of food)
'plate slyly hidden regularly by australian' is the wordplay.
'hidden regularly' means one should take alternating letters.
'by' says to put letters next to each other.
'australian' becomes 'a'.
'plate'+'slyly'='plateslyly'
The alternating letters of 'plateslyly' are 'paell'.
'paell'+'a'='PAELLA'
(Other definitions for paella that I've seen before include "Spanish course" , "Saffron-flavoured rice dish" , "Spanish dish of rice, chicken, seafood etc cooked in a pan" , "Spanish dish of rice, shellfish, etc" , "Traditional Spanish dish" .)