Preheat oven to 350 degrees F. Grease a 3-quart baking dish; set aside. Cook pasta according to package directions, adding dried tomatoes to boiling water with the pasta; drain.
For sauce, in a large skillet cook mushrooms, sweet peppers, and onion in hot oil over medium heat until tender. Stir in flour. Gradually stir in milk and the 1 cup water. Cook and stir until slightly thickened and bubbly. Gradually add the 2 cups cheese, stirring until melted. Season to taste with salt and black pepper.
In a large bowl combine cooked pasta mixture, sauce, and turkey. Transfer mixture to the prepared baking dish. Sprinkle with almonds.
Bake, covered, about 30 minutes or until heated through. Let stand for 5 minutes before serving. If desired, sprinkle each serving with additional cheese.