Preheat the soup jar by filling it with hot water and closing the lid.

Cut the green onion into small slices using kitchen scissors.

Boil water in a pot and cook the somen noodles according to package instructions. Drain, rinse with cold water, and drain again thoroughly. Toss with sesame oil and place in a sealed container.

In the same pot, add the soup ingredients (sake, salt, chicken broth powder, ginger, water), chicken tenderloin, and green onion. Bring to a boil, skim off any foam, and simmer for 2 minutes until the chicken is cooked. Remove the chicken and shred it into bite-sized pieces.