Combine the marinade ingredients in a bowl and mix the chicken in. Marinade for 30-60 minutes.
Heat the oil in a large pot or Dutch oven to 350°F.
Stir in the additional ¼ cup cornstarch with the chicken.
Slowly drop chicken pieces into the hot oil and fry until golden brown, about 3-5 minutes. Cook the chicken in 3-4 batches to ensure you don't crowd the pan.
Drain the chicken on paper towels and place place in a bowl. When all chicken is done, toss it with the salted egg sauce and sprinkle with the salt.
Serve immediately with steamed jasmine rice.
Salted Egg Sauce:
Melt the butter in a small saucepan over medium low heat.
Add in the garlic, Thai chilies, sugar and curry leaves, Stir and cook for 20-30 seconds.
Add in the egg yolks, mashing them together with the rest of the ingredients to make a sauce. Cook until it starts to get foamy. Pour over the fried chicken pieces and toss to coat the chicken.
Notes
Do not overcrowd the pot when frying the chicken or the temperature of the oil will fall too much, causing your chicken to be soggy and oily. Cook in 2-3 batches. Make sure the oil is hot (350°F) before frying.
If the sauce is too thick, add an addition 1-2 tablespoons of butter OR 1-2 tablespoons of coconut milk.
If your salted eggs come uncooked, boil them in water for 10 minutes then place them immediately in an ice bath for 30 minutes. Peel and use like normal. You can also separate yolks from whites, then cook the yolks in a microwave or steamer.