Preheat oven to 350. Saute first 2 ingredients in hot oil for about 5 minutes until tender. Add garlic, saute 1 minute. Stir in soup and next 4 ingredients, remove from heat.
Spread 1 cup soup mixture in lightly greased 13 X 9 baking dish. Arrange 24 tortilla quarters, slightly overlapping, over soup mixture, top with 3 cups chicken, 3/4 cups of the cheeses, and 1 1/2 cup soup mixture; repeat layers once. Top with remaining 24 tortilla quarters, soup mixture and cheese.
Bake at 350 for 45 - 50 minutes or until bubbly and golden. Remove from oven to a wire rack, and let stand 15 minutes before serving.