In a mixing bowl, combine all-purpose flour, cornstarch, baking powder, salt, and white pepper. Gradually stir in water, whisking until smooth. Add egg and vegetable oil, mixing until slightly thick yet pourable. Let rest for about 10 minutes.

Cut chicken into bite-sized pieces. Dip each piece into the prepared batter, ensuring coverage, then let excess batter drip off.

Heat vegetable oil to 350°F (175°C) in a deep skillet. Fry battered chicken pieces in small batches for about 5-6 minutes until golden brown and crispy. Drain on paper towels.

In a medium saucepan, combine honey, soy sauce, rice vinegar, grated ginger, minced garlic, and red pepper flakes. Heat until simmering, about 5 minutes. Mix cornstarch with water to create a slurry, stir into sauce and cook until thickened, about 2-3 minutes.

Toss the fried chicken in the sauce until well coated, allowing the flavors to meld together before serving.

Transfer glazed chicken to a serving platter. Garnish with sesame seeds and chopped green onions. Serve immediately.