To thicken sauce: (mix the add in increments at end, as needed)
Start rice cooking.
* Using a vegetable peeler, peel a couple of thin strips from the side of the orange. (Using a vegetable peeler allows you to just take the peel and none of the bitter pith). Finely dice peel (about 1/8-inch squareuntil you have about 1 1/2 Tbsp. Add 1 Tbsp. of the diced orange peel to your sauce. Reserve the remaining 1/2 Tbsp. to stir fry with your chicken.
Prepare sauce by combining sauce ingredients in a medium bowl. Whisk well to combine. Set aside.
Heat oil in skillet or wok over medium-high heat. Add chicken and reserved diced orange peel and cook, stirring occasionally, until chicken is cooked through. If using additional vegetables, add them after chicken is partially cooked. Add sauce. Bring mixture to a boil, then reduce heat and allow to simmer while your rice/veg cooks (5-10 minutes).
In a small bowl, stir together the cornstarch and water. Add about half of it to simmering sauce and cook, stirring regularly, until sauce thickens. If not thick enough, add more, as needed, until sauce is as thick as you'd like. Serve over rice.
If you'd like to try velveting your chicken, combine the following ingredients in a medium bowl. Pour over cut, raw chicken chunks. Stir, cover and refrigerate for 30 minutes.
2 egg whites
2 Tbsp. veg oil
2 Tbsp. cornstarch
2 tsp. rice vinegar
1 tsp. salt
After 30 minutes, drain. Heat 4 inches of water to boiling in a medium/large saucepan. Once boiling, add drained chicken chunks and cook until opaque, about 1 minute. Remove to a plate, then proceed with recipe.
Be sure to read the "Cook's Notes" in the original post, for more tips, options, substitutions and variations for this recipe!