I live out in the east end of North York, and yet my parents will brave the 401 traffic to specifically come here for lunch (and the occasional dinner) whenever they feel like lunching out. Their dim sum is some of the best in the city, and they are very flexible here. If you want a lobster for lunch (usually considered a dinner item) they have no problem making it for you.
Their weekend dimsum menu is better (there are more items on it) but you'll have to brave the crowds of locals that come out for lunch. It's located in the back of the Doubletree Hotel, and they will validate your parking ticket for 2 hrs free parking if you dine in the restaurant. It's a bit on the pricy side, but worth it.
The service is always excellent and food is always beautifully presented and delicious.