We have previously been regular patrons of Punitha's Tiffin in Albany Road, which is now apparently defunct (shutters permanently shut, no-one answers the phone, etc.).
Madras in Wales offers a similar South Indian cuisine, extremely well cooked and presented, in more comfortable surroundings, and at the same very reasonable prices. And as a bonus you can take your own bottle or cans if you want to drink alcohol.
As long as you're not seated next to the extremely rude and arrogant doctor and his wife that we were treated to last night, you can't do much better than this.