Requirement to do porridge? (7)

I believe the answer is:

oatmeal

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'porridge?' is the definition.
(I know that oatmeal is a type of porridge)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for oatmeal that I've seen before include "ground food!" , "The material for porridge" , "Sort of beige" , "It's boiled for porridge" , "AA Motel (anag.)" .)

I've seen this clue in The Telegraph.

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