To make soup: Heat sesame oil in pressure cooker over medium heat. Add leeks, and cook 2 to 3 minutes, or until soft. Stir in squash, rice, edamame, broth, kombu, and 21/4 cups water. Close pressure cooker, and bring up to high pressure. Cook 6 minutes.
Allow the pressure to return to normal on its own. while you make the green onion relish.
To make Relish: Heat small saucepan over medium-high heat, and add grapeseed oil. Add ginger and green onions, and cook 1 to 2 minutes, or until onions are wilted but still bright green. Remove from heat, and season with white pepper and salt, if desired.
Remove kombu from soup. Thinly slice kombu strip; stir into soup. Ladle ?1 cup soup into bowl, stir in miso, then stir miso mixture into soup pan.
to serve Stir 1 Tbs. Relish into each serving of soup.