Spread slices of sweet potatoes in a greased metal dish of 13 inches x 9 inches. Set aside.
In a measuring cup, mix brown sugar, butter, orange zest and juice, ginger, salt, pepper. Cover and heat in microwave, at high power, for about 1 minute or until butter has melted and brown sugar is dissolved. Mix well and pour on the sweet potatoes.
Cook in a preheated oven of 375 F for about 45 minutes or until sweet potatoes are tender (baste with orange glaze sometimes during cooking). Keep cooking under preheated grill for about 3 minutes or until sweet potatoes are golden and glazed. When ready to serve, sprinkle with green onions.