Whisk together the sauce ingredients: 2 tablespoons ketchup, minced garlic, optional chili paste, 1/4 cup honey, 1/3 cup soy sauce, 1/4 cup rice vinegar, 2 tablespoons brown sugar, 1 tablespoon cornstarch, 1/2 cup water, and 2 teaspoons sesame oil. Set the sauce aside.
In a large shallow bowl, combine 1 cup cornstarch, 1/4 cup flour, 1/2 teaspoon salt, and 1/4 teaspoon ground black pepper.
Beat the 2 eggs in a separate bowl.
Heat about 2 inches of canola oil in a deep frying pan over medium-high heat until hot but not smoking (about 350°F / 175°C).
Dip the chicken chunks first into the beaten eggs, then toss them in the cornstarch-flour mixture to fully coat. Work in batches to avoid crowding.
Fry the coated chicken in batches until golden and crispy, about 4–6 minutes per batch depending on size. Use tongs or a slotted spoon to turn as needed.
Transfer cooked chicken to a plate lined with paper towels to drain.
Discard the frying oil, wipe the pan clean, then return the pan to medium heat. Pour the prepared sauce into the pan and bring it to a simmer until it thickens and becomes glossy, about 2–3 minutes.
Add the fried chicken to the simmering sauce and toss to coat evenly, heating through for 1–2 minutes.
Serve immediately, sprinkled with sliced green onions and additional sesame seeds if desired.