Directions

1. Set Skillet to 300ºF and add butter. Stir in flour, salt, and pepper until smooth.
2. Set Skillet to 350ºF, gradually add in milk and bring to a boil, stirring frequently.
3. Stir until thickened. Turn off and stir in cheese until melted.
4. Add potatoes and onion, and cover.
5. Reduce to 275ºF and let bake for 1 hour or until fork tender.