Au Gratin Potatoes

In my Smoked Chicken recipe, I included a picture of au gratin potatoes that prompted several people to ask for the recipe.  Here it is...

Printable Recipe

Ingredients
6 medium potatoes, peeled and thinly sliced
3 Tbsps. butter
3 Tbsps. all-purpose flour
1 ½ teaspoons salt
⅛ teaspoon pepper
2 cups 2% milk
4 ounces shredded cheddar cheese
½ cup chopped onion

Directions

Preheat oven to 350°. In a large saucepan over low heat, melt butter. Add flour, salt & pepper until stir until smooth. Gradually add milk. Bring to a boil and cook for 2 minutes or until thickened, stirring constantly. Remove from heat and stir in cheese. Once the cheese has melted, add potatoes and onion.

Pour into a greased 2-qt. casserole dish. Cover and bake 1 hour, then uncover and bake another 30-40 minutes (or until the potatoes are tender).