Canvas and Cream do clearly have a place in the Forest Hill food landscape. I love the interior and the atmosphere. But I haven't eaten there for a long time, not since other lunchtime venues became available. I personally find the food overpriced and underflavoured, and the coffee dire. The service is fine - not outstanding, but efficient. They do have a fabulous selection of cakes, though.
A few years ago my OH and I had the Winter Wonderland New Year's Eve dinner in the gallery and the food was really excellent. I don't know if they brought someone else in to cater that, different from the daytime chefs.