I chanced upon Manna @ Lau Pa Sat and discovered that they serve buckwheat cold noodles, which it not commonly found at hawker stalls. Of course, they serve other regular dishes including bulgogi, bibimbap, ramyeon etc.
The stall is located somewhere near Cross Street, furthest corner from Boon Tat Street.
The main deciding factor for delicious cold noodle is really the sauce and the texture of the noodle. Sounds simple but i am sure it requires to make sure that the noodles do not clamp together after cooking in hot water and running through ice water...
The sauce is the main ingredient that spices up the plain, cold noodle. The other ingredients including the meat, egg and vegatables are garnishes (at least to me).