Broth:
- Bring scallions, carrots, garlic, ginger, kombu, stock, and bonito flakes to boil in a large heavy pot.
- Reduce heat and simmer, skimming occasionally, until stock is reduced to about 8 cups, 1 hour or so. Strain stock into a clean pot; add soy sauce.
Do ahead: Broth can be made 2 days ahead. Let it cool; cover and chill.
Ramen and Assembly:
- While the broth is simmering, bring a medium pot of water to a boil. Carefully add eggs and boil gently 7 minutes (egg yolks will be shiny yellow and almost jammy; egg whites will be just set).
- Using a slotted spoon, transfer eggs to a bowl of ice water to stop cooking; let it cool. Peel; set aside.
- Return broth to a simmer (it should be very hot). At the same time, cook noodles in a large pot of boiling water according to package directions until al dente; drain (no need to add salt to the water as the ramen contains salt).
- Divide noodles among deep bowls. Top with sliced turkey, placing it off to one side. Ladle broth over turkey and noodles.
- Halve eggs and place one half egg on top of the noodles in each bowl. Mound some sliced scallions next to the egg and tuck half a sheet of nori along the edge of the bowl so half of it is sticking out.
- Serve ramen drizzled with chili oil, sesame oil and soy sauce and topped with shichimi togarashi.