1 1/2 pounds boneless, skinless chicken breasts, cut into 1-inch chunks
1 cup 2 tablespoons cornstarch, divided
2 large eggs, beaten
1 cup vegetable oil
1/2 teaspoon sesame seeds
1 green onion, thinly sliced
FOR THE MARINADE
1 cup chicken broth
1/2 cup freshly squeezed orange juice
1/2 cup sugar
1/3 cup distilled white vinegar
1/4 cup soy sauce
2 cloves garlic, minced
1 tablespoon orange zest
1 teaspoon Sriracha, or more, to taste
1/4 teaspoon ground ginger
1/4 teaspoon white pepper
To make the marinade, whisk together chicken broth, orange juice, sugar, vinegar, soy sauce, garlic, orange zest, Sriracha, ginger and white pepper in a large bowl.
In a gallon size Ziploc bag or large bowl, combine chicken and 2/3 cup of the marinade; marinate for at least 30 minutes, turning the bag occasionally. Drain the chicken from the marinade, discarding the marinade.
Heat remaining marinade in a medium saucepan over medium heat. Bring to a boil and stir in 2 tablespoons cornstarch combined with 2 tablespoons water. Cook, stirring frequently, until thickened about 1-2 minutes; keep warm.
Working one at a time, dip the chicken into the eggs, then dredge in remaining 1 cup cornstarch, pressing to coat.
Heat vegetable oil in a large saucepan. Working in batches, add chicken and fry until golden brown and cooked through, about 1-2 minutes. Transfer to a paper towel-lined plate; discard excess oil.
Serve chicken immediately, tossed or drizzled with the marinade, garnished with sesame seeds and green onion, if desired.