Cut the chicken into bite-sized pieces and marinate them in orange juice for 30 minutes.
Heat oil in a wok to 350°F.
Remove the chicken from the marinade, coat it in cornstarch, and discard the marinade.
Fry the chicken in batches for 5 minutes, ensuring the pieces don’t stick together.
Transfer to a wire rack over a baking sheet.
Clean the wok and return it to medium-high heat.
In a bowl, whisk together chili garlic sauce, tomato paste, fresh orange juice, soy sauce, mirin, and black pepper.
Add chile oil, orange peel strips, and minced garlic to the wok, cooking for 3 minutes.
Pour in the prepared orange sauce mixture and bring it to a boil.
Make a slurry by mixing cornstarch with water and stir it into the simmering sauce. and let it cook for 5 minutes.
Add the fried chicken, tossing to coat evenly.
Serve hot, garnished with scallions, sesame seeds, and diced orange.