Ham Tetrazzini

1 (7 oz) package spaghetti
½ lb fresh mushrooms, sliced
¼ cup chopped onion
¼ cup butter, melted
¼ cup flour
2 cups milk
2 cups half-and-half
½ tsp salt
¼ tsp pepper
1/8 tsp garlic powder
¾ cup grated Parmesan cheese, divided
2 cups diced cooked ham

Cook spaghetti according to package directions, omitting salt.  Drain well, and set aside.
Saute mushrooms and onion in butter in a large skillet until tender.  Add flour, stirring until smooth.  Cook 1 minute, stirring constantly.  Gradually add milk and half-and-half, stirring constantly, until mixture is thickened and bubbly.  Stir in seasonings and ½ cup Parmesan cheese.

Spoon half of spaghetti into a lightly greased 12x8x2 inch baking dish.  Pour 1/3 of sauce over spaghetti; sprinkle with half of the ham.  Repeat layers, ending with sauce over the last layer of ham.  Sprinkle the remaining ¼ cup Parmesan cheese over casserole.  Bake at 350° for 25 minutes.  Yield:  6 servings