Chilled Avocado Soup with Kombu

You can take pretty much any vegetable, puree it, and make soup. If you want to reinvent a familiar staple, just change your notes. In my vichyssoise, for example, I use lobster stock instead of the more predictable chicken. For this avocado soup, it’s dashi, which is a foundation of Japanese cuisine. The broth, flavored with kombu (sea kelp), is the basis of noodle soups like ramen, soba, and udon, among other things. Kombu, they say, is one of the greatest sources of glutamates, the amino