11 hours ago, KennethT said:I get them at my local H-Mart which calls them "Korean Leeks"
Yes. In Mandarin Chinese, they are 大葱 (dà cōng), literally 'big onion' but often translated as leeks. They are also known as Japanese leeks.
As a kid growing up in East Scotland* they were known as sybows but pronounced sybies in my local dialect.
The history of the names is interesting. First known reference and from 1362 is as 'chibols'. This is derived from a Northern French dialect name, chiboule. The Scots sybow was a 16th century adaptation of chibol.
* Wikipedia claims incorrectly that this name is from the west of Scotland. No, it ain't. In the west of Scotland they are referred to as 'spring onions'. There are many other names used in different places.