Toast Sesame Seeds: Place the sesame seeds in a dry skillet over medium heat. Cook, stirring frequently, just until lightly browned and fragrant. Set aside to cool.
Prepare Chicken: Toss the chicken pieces with egg, 3 tablespoons cornstarch, and soy sauce. Refrigerate for 15 minutes.
Prepare Sauce: In a small bowl, whisk together broth, brown sugar, 2 tablespoons cornstarch, soy sauce, sesame oil, ginger, and garlic.
Cook Chicken: In a 10-inch skillet, heat the vegetable oil over medium-high heat. Add half of the chicken and stir-fry until browned and almost cooked through, about 5 minutes. Transfer the fried chicken to a bowl and repeat with the remaining chicken.
Thicken Sauce: Whisk the sauce and add it to the skillet along with all of the chicken. Cook over medium-high heat while stirring until thickened, about 3 to 4 minutes.
Finish and Garnish: Stir in the sesame seeds. Garnish with green onions. Serve and enjoy!
Notes
To store leftover sesame chicken, place it in an airtight container and refrigerate for up to 3-4 days. When reheating, use the stovetop or microwave until heated through.