Pre-prepared meal was bland according to Spooner (6,5)
I believe the answer is:
packed lunch
'bland according to spooner' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.
'pre-prepared meal' is the wordplay.
'pre-prepared' becomes 'packed' (I can't explain this - if you can you should give a lot more credence to this answer).
'meal' becomes 'lunch' (lunch is a kind of meal).
'packed'+'lunch'='PACKED LUNCH'
'was' is the link.
Can you help me to learn more?
(Other definitions for packed lunch that I've seen before include "Food carried on a day trip" , "Ready-prepared midday meal in container" , "Cold meal (eg, taken to school)" , "Meal to be carried" .)