The night before the meal, place the giblets, neck, any vegetables or spices in a slow cooker.
Add 8 cups of water.
Set to low and go to bed.
Just before serving, strain the stock.
For every 2 cups of stock, you need 4 tablespoons of butter and 3 tablespoons of flour/starch.
Melt the butter in a saucepan over medium high.
Add the flour/starch. Stir well until evenly distributed.
Stir in the stock.
Bring to a boil and stir until gravy has thicken to your liking.