Cut the chicken thighs into bite-size pieces and place in a bowl. Sprinkle with dash of salt and sugar and let it marinade for about 30 minutes. Place the corn starch in a shallow plate and egg wash in another bowl
Preheat oil to 325 F. Dip the chicken in the egg wash and then coat with the corn starch and fry in the oil until golden brown and cooked through (no longer pink and bloody). Remove and place on the absorbent paper towel
In a wok or skillet, preheat about 2 Tbsp of oil and stir-fry curry leaves, chili until really fragrant, about 1 minute or so, add in the salted egg yolk and stir-fry for about 1 minute, it will start to bubble, that's normal. It should start to smell amazing. Stir in the fried chicken and make sure every piece is coated by the salted egg yolk sauce. Dish out onto serving platter and garnish with cilantro and serve immediately