As promised to Aj. Camilee,
The diner's place in 'In The Mood for Love' is called 'Goldfinch Restuarant'!
Address:
Goldfinch Restaurant (also ‘Cafe de Goldfinch’)
G/F, 13-15 Lan Fong Road
Causeway Bay
Hong Kong
Tel: 25777981
Nearest MTR: Causeway Bay, exit F
found two blogs from those who went to the diner :))
http://tastytreats.wordpress.com/2007/08/12/are-you-in-the-mood-for-love/
http://www.greentea.tk/2011/03/in-mood-for-hong-kong.html