Heat oven to 325 F. Remove giblets and neck from turkey. Rinse turkey inside and out with cold water; pat dry with paper towels. Place turkey, breast side up, on rack in shallow roasting pan.
In small bowl, combine flavor enhancer, salt and pepper. Rub spice mixture on outside of turkey and inside cavity. If desired, fill with your favorite stuffing.
Combine margarine, sage and thyme; brush half of mixture over turkey. Cover turkey with loose tent of foil.
Bake at 325 F. for 15 minutes per pound (20 minutes per pound if stuffed), about 3 to 4 hours or until meat thermometer inserted into thickest part of thigh registers 180 to 185 F.
To brown turkey, remove foil for last hour of baking. Baste turkey with remaining margarine mixture. Juices should run clear when thigh is pierced with a fork and leg joint should move easily. Let turkey stand 15 minutes before carving.