Season the chicken with a pinch of salt and pepper, then coat it evenly in flour.
Combine 1 cup of water with sugar, lemon zest, and juice in a saucepan, then set it aside.
Combine sweet rice flour with water until you achieve a thin, pancake-like batter consistency. Then, sprinkle in a pinch of salt and pepper.
Preheat the oil in a wok until it reaches 400 degrees F (200 degrees C). Coat chicken in batter, then fry in batches until golden brown, about 4 to 5 minutes per side. Place the fried chicken on a serving platter to keep warm.
Heat the lemon mixture over medium-low heat in a saucepan. Dissolve cornstarch in 6 tablespoons of water and add it to the saucepan. Stir until it thickens into a syrup-like consistency. Quickly blend in the egg yolk until well combined. Remove from heat.
Dice the chicken into bite-sized pieces, then drizzle with the zesty lemon sauce. Finish by adorning with fresh lemon slices.