Begin by cutting boneless, skinless chicken breasts into 1-inch pieces. In a mixing bowl, season the chicken with salt and pepper. Dip the seasoned chicken pieces into the lightly beaten eggs, ensuring they are fully coated. Transfer them into a mixture of all-purpose flour and cornstarch, pressing lightly to create a crisp coating.

Heat oil in a deep skillet or frying pan over medium-high heat until it reaches 350°F (175°C). Gently add the coated chicken pieces in batches. Fry each batch for about 3-5 minutes or until golden brown and crispy. Remove the chicken with a slotted spoon and let it drain on paper towels.

In a saucepan, combine lemon juice, sugar, and water over medium heat. Stir the mixture continuously until the sugar dissolves. Allow the sauce to come to a gentle simmer, cooking for around 3-5 minutes until it thickens slightly.

Once the sauce is ready, add the crispy fried chicken to the saucepan. Gently toss to coat each piece in the glaze. Transfer to a serving plate and garnish with sesame seeds, sliced green onions, and grated lemon zest. Serve warm.