Cut the chicken breast into medium bite-sized cubes.
Marinate: In a bowl, mix the egg white, rice vinegar, kecap manis (or oyster sauce), salt, sugar (if using), and 2 teaspoons of corn flour. Add the chicken pieces and mix well. Cover and marinate in the fridge for 30 minutes.
Coat the marinated chicken with additional corn flour.
Fry the chicken in hot oil at 180°C (356°F) until golden and crispy (about 2-3 minutes). Remove and set aside on paper towels.
Make the sauce: In a pan over medium heat, melt the butter with a splash of oil. Add the sliced chilli and cook for 1-2 minutes.
Add the curry leaves and cook for another 1 minute until fragrant.
Add the minced garlic and cook for 30 seconds (do not burn).
Pour in the evaporated milk. Season with salt, black pepper, and sugar (if using). Cook on low-medium heat until the sauce thickens slightly.
Add the fried chicken back into the pan and toss gently for 1-2 minutes until the sauce coats the chicken and thickens nicely.
Turn off the heat, garnish with chopped scallions and serve immediately.
Enjoy! 🔥