Start by cutting the chicken into bite-sized pieces for even cooking. Season it with salt, pepper, and garlic powder, then mix well. Add the egg and coat the chicken thoroughly before tossing it in cornstarch.
Heat oil in a pan over medium-high heat until hot enough for frying. Carefully add the coated chicken pieces and fry until golden brown and crispy. Remove and place on paper towels to drain excess oil.
In a separate pan, melt butter over medium heat and sauté minced garlic until fragrant. Add curry leaves and sliced chilies, letting them release their aroma. Pour in evaporated milk and stir gently to combine.
Add sugar and salt into the sauce and adjust to taste. Toss the crispy chicken into the sauce, ensuring every piece is well coated. Cook briefly so the chicken absorbs the creamy flavors without losing crunch.
Turn off the heat once everything is well combined and glossy. Optionally sprinkle crispy chicken skin on top for extra texture. Serve immediately while hot for the best experience