hói cho sà léut
海草 is seaweed (海 is ocean or sea, and 草 is grass, so 海草 is sea grass). 沙律 is the Cantonese loanword for salad (pronounced sà léut), while the Mandarin loanword for salad is 沙拉 (pronounced shā lā).
Seaweed salad is a standard dim sum item.
jellyfish salad