They are well-known for their fresh hand-made noodles with Shrimp Roe (you can buy the Shrimp Roe by the bottle but I'm not sure how immigration will feel about you exporting some though). Their Crab Congee is popular and excellent. I can close my eyes and taste the inherent sweetness in their Dungeness crab.
Wong Kun Sio Kun is actually a Bib Gourmand pick in the Michelin guide (2015). It is constantly featured in Chinese media so I first heard of it from my sister-in-law. The following review is from my 2 separate visits to the restaurant.