1. Combine onion and frozen mixed vegetables in 2-quart casserole. Cook, covered, on Full Power for 7 to 9 minutes, or until onion is tender and vegetables are done. Stir in soup, chicken, mushrooms, and 1/4 teaspoon salt. Set aside.

2. Combine sweet potatoes, melted butter, egg, 1/4 teaspoon salt, and spices in mixing bowl. Mash. Line 9-inch pie plate with potato mixture, building up edges 1/2-inch higher than plate.

3. Spoon chicken mixture into sweet potato crust. Cover with heavy-duty plastic wrap. Heat, covered, on Full Power for 7 to 10 1/2 minutes, or until heated through.