Add water, chicken stock powder, lemon juice, grated garlic, sesame oil, roasted sesame seeds, and black pepper to the bowl; mix thoroughly and refrigerate until needed.
3
Bring water to a boil in a small pot, add a pinch of salt, carefully place the egg in the water, and boil for 7 and a half minutes. Remove and immediately cool in ice water.
4
Trim excess skin and fat from the chicken thigh. Place it in a heat-resistant container and coat with sake, soy sauce, mirin, grated garlic, chicken stock powder, and sesame oil; mix well. Arrange skin-side down, loosely cover with plastic wrap leaving a vent, and microwave at 600W for 1 minute and 30 seconds.
5
Remove the chicken, flip it over, cover again with plastic wrap, and microwave at 600W for 1 minute. Cover and let cool, allowing residual heat to finish cooking the meat.
6
Place somen noodles in a heat-resistant bowl, pour boiling water over them until covered, and quickly separate them with chopsticks. Microwave uncovered at 600W for 3 and a half minutes.
7
Drain the hot water, immediately rinse the noodles thoroughly with cold water while massaging them to cool and drain well.
8
Peel the cooled egg and cut the cooked chicken into bite-sized pieces.
9
Microwave the juices from the cooked chicken at 600W for 30 seconds, add to the chilled scallion broth from step 2, and add an ice cube to keep it cold.
10
Add the drained noodles to the broth and toss to combine. Transfer to a serving bowl, top with chicken and egg, and serve.