Flatten chicken breasts between two sheets of wax paper to about 1/4 inch thick. Saute chicken over medium-high heat with a couple tablespoons vegetable oil until there is no pink showing.
In medium saucepan, add ginger, sugar, cornstarch, orange juice, vinegar, soy sauce and butter. Cook over medium heat until thick.
Serve chicken over a bed of rice and spoon orange sauce over chicken. (About 350 calories) Serves 4.