Begin by slicing 1 pound of boneless chicken breasts or thighs into thin strips for even cooking. In a mixing bowl, combine the sliced chicken with 1 egg white, 1/4 cup cornstarch, 1/2 teaspoon salt, and 1/2 teaspoon pepper. Mix thoroughly to coat the chicken evenly, then let the mixture rest for 10 to 15 minutes.

Heat 2 to 3 tablespoons of vegetable oil in a large skillet over medium-high heat until shimmering. Carefully add the marinated chicken in batches, ensuring they are not overcrowded. Fry for 4 to 5 minutes on each side, until golden brown and crispy.

Using the same skillet, reduce the heat to medium and add 1 tablespoon of sesame oil. Add 2 tablespoons of minced garlic, 1 tablespoon of minced ginger, and 2 to 3 dried red chilies. Sauté for 1 to 2 minutes until fragrant.

In the same skillet, incorporate 1/2 cup tomato ketchup, 2 tablespoons of soy sauce, 1 tablespoon of chili garlic sauce, 1 tablespoon of vinegar, and 1 tablespoon of sugar or honey. Stir and let simmer for 2 to 3 minutes. If too thick, add 1/4 cup of water.

Add the fried chicken back into the skillet and toss in the sauce to coat thoroughly. Simmer for an additional minute.

Transfer the dish to a serving plate and top with sliced green onions, toasted sesame seeds, and optional fried onion or bell pepper strips. Serve immediately.