Kelsie has done an amazing job, compiling this spreadsheet of South East London businesses which are still providing service during the current crisis:
Please help out by editing and improving this sheet
I’ve seen some amazing efforts along these lines. Here’s one focused on SE23 and SE4 maintained by some locals.
The Resident magazine published another list yesterday, cover bakeries, fishmongers, green grocers, food collection and delivery services. It’s a wider area, but has quite a few Forest Hill favourites listed in the “restaurants & cafes offering collection & delivery” section: