Prepare the Chicken: In a bowl, toss the chicken pieces with the beaten egg. In a separate shallow dish, whisk together the cornstarch, flour, salt, and pepper. Dip each egg-coated chicken piece into the cornstarch mixture, ensuring it's fully coated. Set aside.

Make the Orange Sauce: In a small saucepan, whisk together the orange juice, orange zest, soy sauce, honey, rice vinegar, garlic, and ginger. Bring to a simmer over medium heat. Add the cornstarch slurry and whisk constantly until the sauce thickens, about 2-3 minutes. Remove from heat and set aside.

Fry the Chicken: Heat the vegetable oil in a large skillet or wok over medium-high heat. Carefully add half of the coated chicken to the pan in a single layer. Cook for 3-4 minutes per side, until golden brown and cooked through. Remove the chicken to a paper towel-lined plate. Repeat with the remaining chicken.

Combine and Serve: Return the skillet to low heat. Add all the cooked chicken back to the skillet and pour the orange sauce over it. Gently toss until all the chicken is evenly coated and glossy. Be careful not to overmix.

Assemble the Bowls: Divide the cooked rice among four bowls. Top with the orange chicken, steamed broccoli, and garnish with sliced green onions and sesame seeds. Serve immediately.