Flatten and Season the ChickenPlace the chicken breasts between two sheets of plastic wrap. Pound them to an even thickness and season both sides with salt and pepper.
Bread the ChickenSet up three shallow dishes: one with flour, one with beaten egg, and one with panko. Dredge each chicken piece in flour, then egg, then panko. Press the breadcrumbs in gently so they stick.
Fry the ChickenHeat oil in a pan over medium heat. Fry each breast for 3 to 4 minutes on each side until golden brown and cooked through. Remove and let rest on a paper towel-lined plate or wire rack.
Make the BrothIn a large pot, combine chicken broth, soy sauce, and miso paste. Stir until the miso dissolves, then add sesame oil and let the broth simmer.
Cook the NoodlesCook the ramen noodles according to package directions. Drain and divide among 4 serving bowls.
Assemble the BowlsPour hot broth over the noodles. Top each bowl with sliced chicken katsu, green onions, and half a soft-boiled egg.
Notes
You can use red or white miso depending on how bold you want the flavor.
If you want extra crispy katsu, fry the chicken a second time for a minute or two just before serving.
Keep leftovers separate—store the broth, chicken, and noodles in different containers and reheat individually for the best texture.