In a small bowl combine the orange juice, orange zest, soy sauce, salt, garlic and brown sugar. Mix well.
Heat oil in a large skillet or wok over medium high heat. When oil begins to bubble, add chicken. Saute until cooked through (no longer pink inside), about 7 to 10 minutes.
Add orange sauce mixture to chicken and cook until sauce begins to bubble. Add flour, a little bit at a time, until sauce has thickened to your liking. Add bean sprouts and cook for 1 minute; serve hot over chow mein noodles.
