1. In a bowl, marinate the chicken breast with sake, grated ginger, salt and black pepper. Set it aside for 15 to 30 minutes.
2. Heat a small nonstick skillet over medium high heat; add oil and swirl to coat.
3. Add marinated chicken and cook for 3 minutes on each side or until golden brown.
4. For the Teriyaki sauce: In a mixing bowl, combine the soy sauce, mirin, tamari and sugar. Stir to mix and dissolve the sugar.
5. When chicken is golden brown and almost cooked after 6 minutes, pour the teriyaki sauce mixture over the chicken.
6. Reduce heat to medium low. Cover and steam it for 5minutes or until the sauce is thicker like glaze sauce and chicken is cooked through.
7. Remove from heat and let it rest at least 5 to 10 minutes.
8. For the broccoli:In a stock pot, boil about 5- 6 cups of water.
9. Add the broccoli florets and blanch them. Remove and drop them in ice water. Drain and set aside.
10. For the buckwheat noodles: In the same pot of boiling water add the buck wheat noodles.
11. When it comes to a boil, add a bowl of ice water and let it cook for 7- 8 minutes.
12. Once done, rinse them in cold water and set in a colander to drain.
13. In a sauté pan, add a tablespoon of sesame oil and heat it.
14. Add the broccoli and buck wheat noodles and sauté gently.
15. Season with salt and pepper.
16. Add the lemon juice and stir it in.
17. Pour in the sesame seeds and mix it in.
18. In a plate, add the buckwheat noodles and broccoli.
19. Slice the chicken and plate it on the noodles.
20. Drizzle the sauce over the meat.
21. Finish off with a drizzle of sesame oil and serve right away.