Depending on the size of the goose you're cooking it takes between 1 hour to 1 hour and 30 minutes to cook the goose.
Place the Goose in the oven at 350 F after preheating the oven to the 350 F and roast the goose in the oven until it turns a golden brown which takes about 1 hour.
Then with a baster, remove as much fat as possible from the roasting pan every 30 minutes if you so desire however it's not required.
Cook the goose until it's cooked good enough for you.
The goose will be fully cooked through when the internal temperature of the goose reaches 165 °F (73.9 °C) throughout the goose.
Using a meat thermometer is a good way to tell when the goose and other meats are fully done and safe to eat.