Place noodle seasoning, Kewpie Mayo, egg in the medium-sized bowl. Mix until incorporated.
Meanwhile, boil chicken broth and add in the Ramen. Cook per package instructions. Remove the Ramen using a strainer. If you are using Soba noodles, submerged the Soba noodles until separated and boil for three minutes. Remove the noodles using a noodle strainer.
Place about 1/4 cup of the prepared broth into the prepared seasoning and mix until the Kewpie Mayo are melted. Place the Soba noodles and pour in the remaining broth. Garnish with onions, egg, and Chashu.