Flourishes a bun with nothing in it; starting dinner soon (7)
I believe the answer is:
abounds
'flourishes' is the definition.
(I've seen this before)
'a bun with nothing in it starting dinner soon' is the wordplay.
'with' means one lot of letters go next to another.
'nothing' becomes 'O' (looks like zero - 0).
'in it' means one lot of letters goes inside another.
'starting' says to take the initial letters.
The initial letters of 'dinner soon' is 'ds'.
'a'+'bun'='abun'
'abun' placed around 'o' is 'aboun'.
'aboun'+'ds'='ABOUNDS'
(Other definitions for abounds that I've seen before include "Is plentiful" , "Exists in large numbers or amounts" , "Exists in large quantities" , "Flourishes" , "Is all over the place" .)