How to Make It
Cook spaghetti according to package directions, omitting salt and fat; drain well. Rinse under cold running water; drain well, and set aside.
Melt the margarine in a large nonstick skillet over medium-high heat. Add mushrooms and next 3 ingredients, and sauté 4 minutes or until tender. Stir in flour, poultry seasoning, and pepper; cook 30 seconds, stirring constantly. Gradually add milk, and cook 1 1/2 minutes or until thickened, stirring constantly. Remove from heat, and stir in 1/4 cup cheddar cheese, stirring until cheese melts. Add chicken, ham, 1/3 cup Parmesan cheese, and next 3 ingredients; stir well.
Combine the spaghetti and chicken mixture in a large bowl; stir well. Spoon mixture into a 13 x 9-inch baking dish coated with cooking spray.
Combine remaining 1/3 cup Parmesan cheese and paprika, and stir well. Sprinkle Parmesan cheese mixture, remaining 1/2 cup cheddar cheese, and almonds in alternating diagonal rows across top of casserole. Bake, uncovered, at 350° for 20 minutes or until bubbly.
Make-Ahead Tips: You can assemble the casserole up to 4 hours ahead of time, omitting the cheese-and-almond topping; cover and chill. Add topping just before baking.