In a large skillet, saute rice and vermicelli in butter until golden brown. Gradually stir in the water, tomatoes and contents of the rice seasoning packets. Bring to a boil. Reduce heat; cover and simmer for 15-20 minutes or until rice is tender. Meanwhile, in a large bowl, combine the chicken, corn, sour cream and 1/2 cup cheese. Stir in rice mixture. Transfer to a greased 3-qt. baking dish. Sprinkle with remaining cheese (dish will be full). Bake, uncovered, at 375 for 20-25 minutes of until heated through. Yield: 8 servings.