In a mixing bowl, combine chicken thighs with soy sauce and 2 tablespoons of cornstarch. Marinate for 30 minutes.

Whisk together lemon juice, sugar, water, 2 teaspoons of cornstarch, and lemon zest in a small bowl for the sauce.

Mix flour with the remaining cornstarch in a shallow plate and toss marinated chicken to coat evenly.

Heat oil in a deep pot to 350°F and fry coated chicken pieces for 5-7 minutes until golden brown.

Remove fried chicken and place on a paper towel-lined plate to drain excess oil.

Combine fried chicken in a skillet, pour sauce over it, and cook for 30 seconds until sauce thickens.

Serve immediately with jasmine rice and stir-fried vegetables.