Dole out a portion of cheddar or a piece of cake (6)
I believe the answer is:
doddle
'a piece of cake' is the definition.
(both can mean something very easy)
'dole out a portion of cheddar' is the wordplay.
'out' indicates putting letters inside.
'a portion of cheddar' becomes 'dd' (I can't justify this - if you can you should give a lot more credence to this answer).
'dole' placed around 'dd' is 'DODDLE'.
'or' is the link.
Can you help me to learn more?
(Other definitions for doddle that I've seen before include "In slang, an easy task" , "pushover" , "Snip" , "Absurdly simple" , "Piece of cake" .)