Step 1

Preheat the oven to 350 degrees F (175 degrees C).

Step 2

Place eggs in a bowl. Combine cornstarch and garlic salt in a second bowl.

Step 3

Dip chicken in egg, then coat in cornstarch mixture.

Step 4

Heat oil in a skillet over medium-high heat. Brown chicken in the hot oil on all sides, sprinkling with onion salt, garlic salt, and pepper while frying, 3 to 5 minutes.

Step 5

Combine sugar, vinegar, ketchup, and soy sauce in a bowl.

Step 6

Place browned chicken in a 9x13-inch casserole dish and pour sauce over top.

Step 7

Bake in the preheated oven until chicken is no longer pink in the centers and juices run clear, 40 to 60 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).