In a mixing bowl, whisk together orange juice, soy sauce, sugar, and vinegar until the sugar dissolves. Add garlic, ginger, and chili peppers, then set aside.

Cut the chicken breasts into bite-sized pieces, season with salt and pepper, and dredge in a mix of flour and cornstarch.

Heat oil in a frying pan and fry the chicken pieces until golden brown and crispy, about 5-7 minutes. Drain on paper towels.

Pour the prepared orange sauce into a wok, heat until simmering, then add the crispy chicken and stir to coat.

Serve immediately over rice or vegetables, garnished with sesame seeds or green onions.