Dealt with some gateaux (3)

I believe the answer is:

ate

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

'dealt' is the definition.
Although both the answer and definition are past participle verbs, I cannot see how one could define the other.

'with some gateaux' is the wordplay.
'with' indicates a hidden word.
'ATE' is hidden within 'some gateaux'.

Can you help me to learn more?

(Other definitions for ate that I've seen before include "upset > Greek goddess" , "Bolted" , "Munched" , "included in one's diet" , "Ingested" .)

I've seen this clue in the Evening Standard.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.