Liu Sha is a famous Cantonese dim sum dish which usually consists of a quicksand filling and bread. Here are some restaurants that may serve quicksand:

1. Cantonese teahouses: Cantonese teahouses usually serve traditional Cantonese dim sum, including quicksand buns. These teahouses are usually located in the Guangdong area in cities such as Guangzhou, Shenzhen and Zhuhai.

2. Hong Kong style teahouses: Hong Kong style teahouses usually also serve Cantonese dim sum such as Liu Sha Bao. These restaurants are usually located in Hong Kong and Guangdong areas.

3. Chinese restaurants: Some Chinese restaurants also serve Cantonese dim sum such as quicksand buns. These restaurants may be located in other parts of China, such as Beijing, Shanghai, and Sichuan.

To summarize, if you want to try quicksand buns, you can head to a teahouse or Hong Kong style tea house in Guangdong or Hong Kong, or try it at a Chinese restaurant in another region. Alternatively, if you want to make your own quicksand buns, you can buy fresh fish and sauerkraut at the market or supermarket and cook them according to the recipe.