We have a new and utterly superb restaurant in Forest Hill. It's called the Perryvale Bistro and Bar, although I'd say it's higher end than your standard bistro. It's run by the people who own the Crooked Well in Camberwell, and they really know what they are doing. Excellent food - not cheap, but quality. Good wine list, local beers, cocktails, bar and bar snacks if you just want a burger and a drink. They've totally revamped the interior and it's a lovely space. We went on Saturday night as part of their soft opening and the service was pretty smooth, and the staff all lovely. There was a relaxed but buzzy atmosphere. All-in-all the best meal I've had in SE23 in the 15+ years I've lived here.
So, um, yeah, I think I'm recommending it.

http://www.theperryvale.com