If using wakame, soak in a small bowl of warm water for 5 minutes until rehydrated. Drain and set aside.
Combine water, kombu, and dried shiitakes in a medium pot. Place over medium heat and slowly bring to just below a boil, about 10-12 minutes. Small bubbles should form around edges but water should not rapidly boil.
Remove kombu just before water boils. Continue simmering shiitakes 5 more minutes. Remove shiitakes, slice thinly, and return to pot.
In a small bowl, whisk miso paste with ¼ cup of the hot broth until completely smooth. Set aside.
Add edamame, bok choy, and green onion whites to the simmering broth. Add tamari if using. Cook 3-4 minutes until bok choy is just tender.
Add spinach, wakame (if using), and tofu. Stir very gently—silken tofu breaks easily. Cook 1-2 minutes until spinach wilts and tofu is warmed through.
Reduce heat to low. Create 4 small wells in the soup by gently pushing ingredients aside. Crack one egg into each well. Cover and cook 3-4 minutes until egg whites are set but yolks are still runny.
Remove pot from heat. Gently stir in miso mixture and nori strips. Do not boil after adding miso.
Carefully ladle soup into 4 bowls, ensuring each bowl gets one egg, plenty of tofu, and greens. Drizzle with sesame oil and sprinkle with green onion greens and sesame seeds.
Notes
Don't boil kombu or miso—both turn bitter.
Whisk miso separately to prevent clumping.
Handle silken tofu very gently—it breaks easily.
Add tofu near the end of cooking so it stays intact.
Runny yolk enriches the broth when broken.
For vegan version, omit eggs, increase tofu to 16 oz and edamame to ¾ cup.
For meal prep, make soup through step 5 on Sunday, store without miso or tofu. Each morning, reheat one portion, add fresh silken tofu cubes, stir in 1 tablespoon miso, poach one egg. Ready in under 10 minutes.
Store broth and vegetables without miso or eggs in the fridge for up to 3 days.
Add miso and poach egg fresh when reheating.
Silken tofu is delicate—it may break apart when reheating, but still tastes good.