Cook noodles according to package instructions until al dente. Drain and toss with oil. Set aside.
Season chicken with salt and pepper.
Heat oil in a large skillet over medium-high heat. Add chicken in a single layer and sear until golden and crispy. Remove and set aside.
In the same skillet, sauté garlic and ginger for 30 seconds until fragrant.
Add soy sauce, brown sugar, and water. Bring to a gentle simmer.
Stir in cornstarch slurry and cook until sauce thickens and turns glossy.
Return chicken to the skillet, add noodles and vegetables. Toss until fully coated.
Garnish with green onions and sesame seeds. Serve hot.