Place potatoes in a saucepan, cover with water and bring to a boil over medium-high heat. Cook for 8 minutes. Drain and place in a greased 2-qt. baking dish.

In a large skillet, cook sausage and onion over medium heat until meat is no longer pink, drain and spoon over potatoes then sprinkle evenly with the cheese.

Whisk the eggs and pour over the mixture.

In a saucepan, melt the butter then stir in flour, salt and pepper until smooth. Gradually add milk. Bring to a boil and stir for 2 minutes or until thickened and bubbly. Pour over cheese. Cover and bake at 350 degrees F for 45-50 minutes or until potatoes are tender.