Green’s Dictionary of Slang

Irish stew adj.

also Irish
[rhy. sl.]

1. true; esp. in the phr. below.

[UK]S.T. Kendall Up the Frog.
[UK]Dodson & Saczek Dict. of Cockney Rhy. Sl.
[UK]R. Puxley Cockney Rabbit.
[UK]M. Coles Bible in Cockney 33: I want you to come back with your youngest brother so I’ll know that what you’ve been telling me is Irish.
[UK]M. Coles More Bible in Cockney 15: This agreement would finally all come to be Irish stew when Jesus Christ came along.

2. blue.

[UK]R. Puxley Cockney Rabbit.

In phrases