Cook the pasta according to package directions, omitting salt and fat.
Preheat oven to 400°.
Place the flour in a medium saucepan. Gradually add the milk, stirring with a whisk until blended. Bring to a boil over medium heat; cook until thick (about 5 minutes), stirring constantly. Remove from heat; stir in 1/2 cup Parmesan, cottage cheese, and next 4 ingredients (cottage cheese through spinach).
Melt butter in a large nonstick skillet over medium heat. Add leek and mushrooms; sauté 7 minutes or until tender. Drain well, and return to pan. Stir in parsley, oregano, and garlic. Spread 1 cup spinach mixture onto the bottom of a 13 x 9-inch baking dish coated with cooking spray. Arrange 3 noodles over the spinach mixture, and top with 1 1/2 cups of the mushroom mixture. Repeat layers, ending with noodles. Top with 1/2 cup spinach mixture.
Cover and bake at 400° for 25 minutes. Uncover and sprinkle with 1/2 cup Parmesan and fontina. Bake an additional 15 minutes or until golden brown. Let stand 10 minutes.