In a medium bowl, toss the chicken pieces in cornstarch until evenly coated.

In a separate bowl, mix the flour and beaten eggs into a thick batter. Dip each cornstarch-coated chicken piece into the batter.

Heat about 2 inches of oil in a deep skillet or wok over medium-high heat. Fry chicken in batches until golden brown and crispy, about 4-5 minutes per batch. Drain on a paper towel-lined plate.

In a saucepan, combine soy sauce, rice vinegar, hoisin sauce, brown sugar, sesame oil, chili garlic sauce, garlic, ginger, and chicken broth. Bring to a simmer over medium heat.

Stir in the cornstarch slurry and cook for 1-2 minutes, until the sauce thickens.

Toss the fried chicken in the sauce until well coated.

Garnish with sesame seeds and green onions if desired. Serve hot over rice or noodles.