Preheat oven to 350°. In a large saucepan, heat oil over medium-high heat. Add onion and mushrooms; cook and stir until tender. Add garlic; cook 1 minute longer. Stir in broth, artichokes, spinach, rosemary, nutmeg and pepper; bring just to a boil. Reduce heat; simmer 5 minutes, stirring occasionally. Stir in Alfredo sauce; remove from heat., Spread 1 cup sauce into a greased 13x9-in. baking dish. Layer with 3 noodles and 2/3 cup mozzarella cheese. Repeat layers 3 times. Top with remaining sauce and mozzarella cheese. Sprinkle with feta cheese, garlic powder and herbs., Bake, covered, 40 minutes. Bake, uncovered, 15 minutes longer or until noodles are tender. Let stand 10 minutes before serving.