Heat a large skillet or wok with the flavorless oil over medium-high heat.
In a large bowl, whisk together the egg, cornstarch, and salt and pepper. Toss the chicken in the egg and cornstarch mixture until each piece is well coated.
When the oil is hot add the coated chicken in batches, making sure not to over crowd the pan. Cook the chicken until they are golden brown and cooked through, about 5-7 minutes. Place the chicken onto a paper towel lined plate to drain and repeat step until all chicken is cooked.
While the chicken is cooking, prepare the sesame sauce. In a small saucepan on medium heat, stir together the soy sauce, sesame oil, brown sugar, rice vinegar, fresh ginger, and minced garlic. Once the sauce is steaming, stir cornstarch and water in a small bowl to create a slurry, then whisk the slurry into the sauce. Cook until sauce thickens, about 3-5 minutes.
Once the chicken is cooked through and golden brown, place into a large bowl and pour the sauce over top. Toss the chicken to coat in the sauce.
Serve the chicken with rice and sprinkle sliced green onions over top.