In a small bowl, combine ⅓ cup tamari/soy sauce, chili sauce, and vinegar. Set aside.
Season the chicken with flour or cornstarch, salt, and pepper. Heat sesame oil in a large skillet over medium-high heat. Add chicken and cook until crispy. Remove from the skillet and set aside.
In the same skillet, add butter and garlic. Cook until garlic is fragrant. Add ginger, shallot, peppers, and scallions. Cook until veggies are soft.
Add noodles and the sauce mixture. Toss to combine and let the noodles soak up the sauce.
Return the chicken to the skillet and add basil. Toss everything together.
Serve hot, garnished with chili flakes and sesame seeds.
