MiYeok JulGi is usually used for a Korean side-dish, MiYeok JulGi BokkEum in Korea. You can buy salted seaweed stems from a Korean or Asian store. Look for them in the refrigerator section. Since they are heavily salted, you will have to soak them in water at least one night before cooking. This is chewy and salty enough to eat without adding extra salt. If you want to a cook small amount and save some for later, cut them (Of course, they should be already soaked in water) into the size you want, and keep them in the freezer.