Place chicken in a roasting pan. Coat with soy sauce and bake at 400 degrees F (200 degrees C) for 30 minutes; reduce heat to 350 degrees F (175 degrees C) and bake for 1 hour.
Drizzle oil over chicken and bake for another 10 minutes.
Remove chicken from oven, place on a platter and keep warm.
To Make Gravy: Put roasting pan on stove; pour chicken stock into pan and bring to a boil, stirring frequently, scraping up bits of caramelized soy sauce. In a small bowl, combine cornstarch and water and mix; stir this mixture into roasting pan and stir until well combined and a nice, thick gravy is made.
