Combine the chicken cubes, egg, 2 tablespoons of cornstarch, and soy sauce in a mixing bowl. Mix thoroughly to coat the chicken evenly, then set aside to marinate.

Prepare the honey garlic sauce by mixing soy sauce, honey, brown sugar, and water in a bowl until well combined.

In a skillet, heat canola oil over medium-high heat. Add minced garlic and chopped ginger, sautéing until aromatic and softened. Pour the soy sauce mixture into the skillet, stirring occasionally as it cooks.

In a small bowl, whisk together cornstarch and water to form a smooth slurry. Gradually incorporate the slurry into the skillet while stirring continuously, allowing the sauce to thicken. Stir in sesame oil and remove the sauce from heat.

For the fried chicken, mix the remaining cornstarch with the all-purpose flour. Coat the marinated chicken in this flour mixture until evenly covered.

Heat frying oil to 375°F (190°C) in a deep pan, ensuring it reaches about 2 inches in depth. Fry the chicken in small batches for approximately 3 minutes, then transfer to a rack to drain.

After letting the chicken rest for 5 minutes, fry it again for 2 minutes or until golden brown and crispy. Remove the chicken from the oil and drain the excess oil.

Toss the fried chicken in the prepared honey garlic sauce until well coated. Garnish with sesame seeds and green onions if desired, then serve immediately.