US breakfast loaf endlessly cooked by nan (7)

I believe the answer is:
granola
'us breakfast' is the definition.
The answer and definition can be both things that one consumes for nourishment as well as being singular nouns.
Maybe there's an association between them I don't understand?
'loaf endlessly cooked by nan' is the wordplay.
'endlessly' means to remove the last letter.
'cooked' indicates an anagram (letters cooked into a new form).
'by' says to put letters next to each other.
'nan' becomes 'gran' (I've seen this before).
'loaf' with its last letter taken off is 'loa'.
'loa' with letters rearranged gives 'ola'.
'ola' put after 'gran' is 'GRANOLA'.
Can you help me to learn more?
(Other definitions for granola that I've seen before include "US breakfast cereal" , "breakfast dish" , "type of cereal" .)