Pea to augment soup (9)

I believe the answer is:

mangetout

I'm a little stuck... Click here to teach me more about this clue!

'pea' is the definition.
I know nothing about this answer so I cannot judge whether this works.

'to augment soup' is the wordplay.
'soup' indicates anagramming the letters.
'to'+'augment'='toaugment'
'toaugment' is an anagram of 'MANGETOUT'.

Can you help me to learn more?

(Other definitions for mangetout that I've seen before include "vegetables" , "Vegetable" , "Edible pea pods" , "Type of pea" , "Sugar peas" .)

I've seen this clue in the Sydney Morning Herald.

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