I remember the Berni Inn, Nassau Street, Dublin 2. It is now The Porter House pub & brewery.

For over 60 years of the 20th century the building Jammets Restaurant.

https://arrow.dit.ie/jamres/

I don't remember any beggarmen,jolly or otherwise,in Restaurant Jammet.
Patrick Kavannagh was wined and dined there by John Betjeman during the Emergency (commonly known elsewhere as World War 2) when the latter was "Press Attaché" to the UK Representative in Eire.