Sea beans are the green tips of the salicornia plant. The beans are soaked overnight before preparing in order to remove some of the saltiness. Sea beans used to just be harvested in coastal areas but are now organically grown on a commercial basis. Use these exotic greens as you would (or as a substitute) for asparagus or green beans.
This is a specialty product that you'll most likely only find in an Asian market or possibly your farmer's market, depending on where you're located.
If you can't find sea beans then you can substitute: