Non-fancy london pub function room for party

[Eggsbaconsausage]

I need to find a pub in London zones 1-2 for a casual party which will be on a Sunday evening. Expecting around 30 guests for drinks and nibbles. I don't want to pay for the room hire but will obviously generate money for the pub by spend on drinks on what might otherwise by a quiet Sunday night for them. This is not a glitzy party, it's for a casual arty crowd so an old boozer or somewhere with a bit of character is preferable to a fancy bar.
Needs to be near public transport links.
Can any London based mumsnetters help please. I haven't lived in London for 10 years so I'm a bit out of touch.

Candid Cafe in Angel offers their space for private hire - very arty.

I’ve also hired the function rooms at the White Hart on Mile End Road / close to Whitechapel station, and the Hercules on the South Bank. Was a couple of years ago but no minimum spend or hire fee, and Sundays particularly are fairly quiet.

The Kings Arms on Tooley Street doesn’t have a function room but can carve out a niche in their main area for a big group - nice place.