Preheat oven to 400°F. Spray a cookie sheet with nonstick cooking spray.
Slice chicken breasts into bite sized pieces.
Place breadcrumbs, salt, and pepper into a gallon size resealable bag. Add the chicken pieces, seal, then shake to coat. Place the chicken pieces in a single layer on the cookie sheet.
Bake about 20 minutes, or until the chicken is cooked through, flipping the pieces after 10 minutes.
While the chicken is cooking, make the sauce. Place water, honey, orange juice, soy sauce, garlic, orange zest, ginger, and pepper flakes to a medium saucepan. Whisk to combine and heat over medium heat until boiling. Add the green onions. Taste the sauce to see if it needs any adjustments: if it’s too sweet, add a bit more soy, or add a few more pepper flakes if you want it a bit spicier.
Stir together cornstarch and cold water until it is smooth. Make sure there are no lumps! Pour the cornstarch slurry into the boiling sauce while whisking. Cook until thick, which will happen fast.
Once the chicken is done, add it to the pot of sauce and stir to coat. Serve hot over rice with a garnish of green onions and sesame seeds.