Travel guide suggest when in Gangzhou to taste Cantonese pasteries. Can you describe what they are made from?

The local pasteries are also called dim sum, which is very famous in Cantonese culture.
The dim sum are always served in small steamer basket and they are made of the rice, flour, vegetables and even meat.
The famous dim sum include Har Gow, Shaomai, Char siu baau, Char siu baau, rice noodles rolls and congee.