Cook the rice according to the package

Stir together the beef and cornstarch in a bowl until coated. Let stand 10-15 minutes.

Heat 2T oil in a wok over medium heat. Add the garlic and ginger; cook, stirring about 30 seconds. Stir in brown sugar, soy sauce, and water. Increase heat to medium-high and stir until sugar is dissolved and sauce boils and slightly thickens, 4 minutes. Transfer sauce to a bowl; clean wok.

Heat 1C oil in wok to 375°. Gently add the beef slices to the hot oil. Fry, stirring briefly, until edges become crisp and begin to brown, about 2 minutes. Transfer beef to paper towels to drain.

Drain oil and return wok to medium heat. Return beef back in wok, then pour in the sauce. Stir once or twice to combine, then add green onion. Bring mixture to a boil and cook about 2 minutes.

Serve the beef mixture over the rice. Garnish with red pepper and sesame seeds if desired.