Marinate the Chicken: Cut the boneless chicken thighs into bite-sized pieces and place them in a large bowl. Add soy sauce, minced garlic, salt, pepper, corn starch, rice flour, soda water, and the egg. Stir well until the chicken is thoroughly coated in a thick batter. Let rest for 20 minutes.

Make the Glaze: In a separate bowl, combine soy sauce, minced garlic, orange juice, chili flakes, honey, oyster sauce, and grated ginger. Mix until fully incorporated, creating a rich sauce. Set aside.

Heat the Oil: Pour oil into a frying pan and heat over medium-high until it reaches 350°F (175°C). Prepare for frying by ensuring marinated chicken is ready.

Fry the Chicken: Add marinated chicken pieces in batches to avoid overcrowding. Fry for 6-7 minutes or until golden brown. For extra crispiness, re-fry for 1-2 minutes and drain on paper towels.

Simmer the Glaze: Pour the prepared glaze mixture into another pan and bring to a gentle simmer over medium heat. Cook for 2-3 minutes, stirring occasionally.

Thicken the Glaze: Combine corn starch with cold water to create a slurry. Slowly add to the simmering glaze, stirring continuously until thickened. Stir in orange zest and simmer for another 30 seconds.

Coat the Chicken: Toss the crispy fried chicken into the glaze on high heat for about 1 minute, ensuring every piece is evenly coated. Serve immediately.