1. Preheat oven to 450 degrees Fahrenheit.
2. Lay onions, lemon, and garlic on the bottom of a roasting pan. Pat chicken dry with a paper towel then rub with thyme, salt, black pepper, and oil. Place in roasting pan and roast in preheated oven for 30 minutes, uncovered.
3. Pour the white wine into pan (around the chicken, not over it), cover pan and cook for another 15 to 20 minutes. Remove from oven and allow chicken to rest for 10 minutes before carving.