Perhaps you could try this website www.evergreen.com. They are specialised in Asian vegetables.

I think it must be Houttuynia cordata (Giap ca in Vietnamese) in particular the green variety (although the Chameleon Plant also has the "fishy" smell).
Quite easy to strike from cuttings from the Asian food stores but often sold as a ground cover in nurseries. Much harder to eradicate from the garden once you get it growing...

Here is a link that might be useful: Houttuynia cordata

Neat,
I have some of this struggling along in a small spot and never knew it was edible. Got it from a friend in WV years ago. I'll test a few leaves out when the plants come up for the spring. If good this plant will be moved to a more choice location.

Thank you Solanum. That is the plant. Perhaps I can buy some at a local Asian market, and grow it from the cuttings. I suppose it would be prudent to put it in a pot so it doe snot spread too much. Actually, I just saw Chameleon variegated variety plant at a local farmers market. Thanks again, Josh