Competence at organising foyer picnic (11)

I believe the answer is:

proficiency

'competence' is the definition.
(proficiency is a kind of competence)

'organising foyer picnic' is the wordplay.
'organising' is an anagram indicator.
'foyer'+'picnic'='foyerpicnic'
'foyerpicnic' with letters rearranged gives 'PROFICIENCY'.

'at' acts as a link.

(Another definition for proficiency that I've seen is " Competence, skill".)

I've seen this clue in The Hindu.

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