Prepare the chicken pieces by washing them thoroughly and patting dry.
Mix 2 tablespoons of thick soy sauce, black pepper, and 1 tablespoon of sugar in a bowl. Marinate the chicken pieces for about 30 minutes to allow flavors to penetrate.
Dip each marinated piece into a mixture of 2 tablespoons of Bestari flour and 2 tablespoons of rice flour, ensuring it's evenly coated.
Heat oil in a deep fryer or large pan until it reaches around 180°C (356°F). Fry the chicken pieces one by one to prevent overcrowding; this will ensure they get crispy. Drain on paper towels after frying.
While preparing the sauce, mix water with salt and slowly add it while whisking continuously to avoid lumps. Once smooth, stir in basil seeds or sesame for a few minutes until the mixture thickens slightly but remains pourable.
Once the chicken is cooled down a bit, dip each piece into the thickened sauce and sprinkle with chili flakes. Garnish with lime leaves (optional) and minced garlic.
Serve immediately to enjoy the best crunch and flavor.