Preheat oven to 350F.
Make the sauce: In a blender process the first seven ingedients of the sauce until smooth. Pass the sauce through a strainer pouring it into into a medium saucepan with the oilve oil and fry over low - medium heat, stirring occasionally, until the froth is gone, 5 - 7 minutes. Turn off the heat and reserve.
Make the chicken-veggie mix: In a large skillet melt the butter, then sautee the onion and garlic for 1 minute. Add the chicken, zucchini, Poblano and corn and, stirring often, cook over low heat for 10 minutes. Season with salt and pepper to taste.
Assemble the Chicken Aztec Casserole: Grease a 13"x9"x2" lasagna baking pan with butter. Place 6 soft corn tortillas at the bottom. It is not a problem if they overlap. Top the tortillas with a third of the chicken mix, spoon with a third of the tomato-chipotle salsa, sprinkle all over with one third of the shredded cheese and dollop with one third of the sour cream. Repeat with 2 more equal layers. Garnish the casserole by topping it evenly with the crumbled Queso Fresco.
Bake for 15 - 20 minutes until bubbly and the cheese has melted. Enjoy!