Ingredients

• 3 tablespoons Butter
• 2 tablespoons All-purpose flour
• 1 1/2 teaspoons Salt
• 1/8 teaspoon Pepper
• 3 cups Milk
• 6 medium Potatoes
• 2 tablespoons Chopped onion
• Shredded cheese (optional)

Instructions

1. In a medium saucepan, melt butter over medium-low heat, then add flour, salt, and pepper; stir continuously to combine. The mixture will puff up; continue stirring to prevent burning. Cook for an additional 3-5 minutes until the roux takes on a nutty aroma.
2. Slowly add in the milk while stirring. Bring to a boil, continue stirring until thickened. Remove from heat.
3. Grease a 2-quart casserole dish. Place half of the thinly sliced potatoes in the casserole; cover with half of the chopped onion and half of the white sauce. Repeat the layers.
4. Cover the casserole and bake at 350 degrees Fahrenheit for about 1 hour. Uncover and bake for an additional 30 minutes.
5. Optionally, shredded cheese may be added to the white sauce if desired.