Dried kelp, or dasima in Korean, or kombu in Japanese, is a very important ingredient in the base broth of many Korean recipes, giving the broth a delicious umami flavor. Kelp is sold in huge sheets in many Asian markets, as well as most whole-foods stores. Choose the thickest you can find. Store in a cool, dry place in an airtight container or zipper-lock bag. Don’t worry if the surface of the kelp has a white powder, it’ll make it more delicious!