1. Position oven rack in lowest third of oven. Heat oven to 350 degrees F. Remove neck and giblets. Rub turkey with vegetable oil.
2. Spread onions in a large roasting pan. Place turkey on top.
3. Roast in 350 degree F oven 30 minutes. Add broth. Tent with foil if browning too quickly. Roast 3 to 3-1/2 hours, until temperature registers a minimum of 180 degrees F in innermost part of thigh and 170 degrees F in breast. Remove to platter.Gravy::
4. Scrape pan drippings into bowl. Skim fat. Melt butter in saucepan. Stir in flour. Whisk in strained pan juices and chicken broth. Add white wine and salt; simmer, stirring, until thickened, 2 to 3 minutes.
Servings Per Recipe: 12; Amount Per Serving: cal.(kcal): 285, Fat, total(g): 13, chol.(mg): 97, sat. fat(g): 4, carb.(g): 5, pro.(g): 34, sodium(mg): 262, Percent Daily Values are based on a 2,000 calorie diet.