Amaranthus. Dunno the species or variety. Lovely stirfried. There is another variety that has white stems. It is delicious in stirfry as well. In Thailand, we only use the very tender tips for cooking. Here in the markets in the US, they were picked rather passed their prime. Maybe the Vietnamese like them at that stage.

Thanks Pitimpinai, that is it! Everyone here is full of knowledge. Ain't nothing I haven't gotten ID yet. THANKS! Yep the tender tips are good. Once they get older, the stem becomes more tougher. Usually if those are the only ones you could find, you can strip the outer part of the stem so it won't be so tough. I've been getting really great tender growths from the ones in my greenhouse, large leaves too.