Step 1: Preheat and Prep

1. Preheat your oven to 400°F (200°C). This temperature is high enough to crisp the chicken without drying it out.
2. Prepare a baking sheet with parchment paper or a light coat of cooking spray to prevent sticking.

Step 2: Prepare the Chicken

1. Cube the Chicken: Cut the chicken into bite-sized cubes for easy coating and even cooking.
2. Coat with Cornstarch: In a bowl, toss the chicken cubes with cornstarch until they are evenly coated. This will help create a crisp texture when baked.
3. Add Seasoning: Lightly season with salt and pepper, if desired.

Step 3: Bake the Chicken

1. Spread the coated chicken cubes on the prepared baking sheet in a single layer.
2. Bake for 20-25 minutes, flipping halfway through, until golden and crispy. Cooking times may vary depending on your oven and the size of the chicken pieces.

Step 4: Make the Orange Sauce

1. Combine Ingredients: In a saucepan, whisk together orange juice, orange zest, soy sauce, honey (or brown sugar), minced garlic, minced ginger, and vinegar.
2. Heat the Sauce: Bring the mixture to a simmer over medium heat, stirring frequently.
3. Thicken with Cornstarch Slurry: In a separate small bowl, mix 1 tablespoon of cornstarch with 1 tablespoon of cold water to make a slurry. Gradually add it to the sauce while stirring until it reaches the desired consistency.
4. Finish with Sesame Oil (optional): Stir in a small dash of sesame oil for added depth.

Step 5: Combine and Serve

1. Once the chicken is done baking, add it directly to the saucepan with the orange sauce. Toss until each piece is coated with sauce.
2. Serve over rice or steamed vegetables, garnished with sesame seeds and chopped green onions if desired.