What does "ongtray" mean?

Question

In "The Bird with a Broken Wing," part of Agatha Christie's story collection, The Mysterious Mr Quin, Inspector Winkfield tells Mr Satterthwaite:

Must find out what terms they were on. That’s where you can be useful to us, Mr Satterthwaite. You’ve the ongtray here, and you can get the hang of things in a way we can’t. Find out what relations there were between the two.

What does "ongtray" mean? Searches on Google mostly yield the same quoted text, with people complaining that searching didn't yield anything useful.

Answer 1

I believe it means "entrée" but I am not entirely sure why Agatha Christie wrote ongtray instead. Checking the meaning of "entrée":

1. The main course of a meal.
   1.1 British A dish served between the first and main courses at a formal dinner.

2. The right to enter or join a particular sphere or group.

- Lexico

(2) fits the context.

Additionally, Google gives some other results for "ongtray" which match "entrée":

• The Brass Bottle, F. Anstey:

  "I was going to ask you, sir, before them parcels came," she began, with a dry cough of disapproval, "what you would like in the way of ongtray to-morrow night. I thought if I could find a sweetbread at all reasonable "

  Seems to fit (1).

• Bring Larks and Heroes, Thomas Keneally, 2016:

  'Ongtray!' called Mrs Blythe. 'She means go in,' Ann hissed at him.

  Maybe fits (2), but I suppose it's a bit of a stretch. Perhaps the same word but in French?

• And The Complete Servant by Samuel and Sarah Adams, 1825 has this entry in a glossary including French words:

  Entrée (ong-tray) Entrance.

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I suppose the use of "ongtray" here perhaps indicates some over-enunciation from the good Inspector.