In a small saucepan, combine 3/4 cup soy sauce and 3/4 cup sugar over medium heat, bringing to a gentle boil for about 2-3 minutes until it thickens slightly. Stir in 1/2 cup crushed garlic, 1/4 cup chopped green onion, 1 tablespoon sesame oil, 1 teaspoon red chili flakes, and 1/2 teaspoon white pepper. Let it boil for another minute before removing it from the heat, then set the sauce aside to cool.

In a large mixing bowl, add 2 pounds of cubed chicken along with 4-5 tablespoons of the prepared garlic sauce, 1 tablespoon cornstarch, and 1 tablespoon vegetable oil. Mix everything thoroughly until the chicken is well-coated. Cover the bowl with plastic wrap and allow it to marinate at room temperature for 30 minutes, or refrigerate overnight for an even richer flavor.

While the chicken marinates, prepare the coating mixture in another bowl by whisking together 1 1/2 cups of flour, 1/2 cup cornstarch, and 1/2 teaspoon salt. To add a hint of flavor, incorporate 3 tablespoons of the garlic sauce into the dry mix, stirring until it forms small clumps.

In a deep frying pan or large skillet, pour in enough vegetable oil to reach about 2 inches deep. Heat the oil over medium-high heat until it shimmers, ideally between 350°F to 375°F (175°C to 190°C).

Once the oil is heated, take the marinated chicken pieces and dredge them in the flour coating, pressing to ensure the mixture adheres well. Working in batches, carefully place the coated chicken into the hot oil, frying each piece for about 3-4 minutes or until golden brown and crispy.

After frying, warm any remaining garlic sauce over low heat until heated through. In a large mixing bowl, toss the crispy fried chicken with the warm sauce until well coated. Serve the savory garlic sauce on the side for dipping.