Step 1: Create the Flavorful Chicken Filling
Preheat your oven to 375°F (190°C). In a large skillet, heat the olive oil over medium heat. Sauté half of the diced red onion for 3-4 minutes until softened. Add the minced garlic and cook for 30 seconds until fragrant. Add the shredded chicken, taco seasoning, and water/broth. Stir to combine and cook for 2-3 minutes. Stir in the black beans, undrained diced tomatoes with green chiles, and thawed corn. Cook for another 3-4 minutes until heated through. Remove from heat and stir in the lime juice. Set aside.

Step 2: Prepare the Creamy Green Chile Cheese Sauce
In a medium saucepan, melt the butter over medium heat. Whisk in the flour and cook for 1 minute to form a roux. Gradually whisk in the milk until smooth. Cook, stirring constantly, until the mixture thickens and begins to bubble, about 3-5 minutes. Reduce heat to low. Stir in the undrained diced green chiles, cumin, and smoked paprika. Gradually add the 2 cups of Pepper Jack and 1 cup of cheddar cheese, stirring until completely melted and smooth. Remove from heat and stir in the sour cream until fully incorporated. Your sauce should be velvety and pourable.

Step 3: Assemble the First Layer
Lightly spray a 9×13 inch baking dish with non-stick spray. Create an even base layer using about two-thirds of the bag of tortilla chips, pressing them down slightly. You want full coverage but not a massive mound.

Step 4: Add the Hearty Filling & Creamy Sauce
Spoon the entire Southwest chicken and bean mixture evenly over the chip layer. Next, carefully pour the creamy green chile cheese sauce over the chicken layer, spreading it gently with a spatula to cover completely.

Step 5: The Final Crispy, Cheesy Layers
Sprinkle the remaining one-third of the tortilla chips over the sauce. Top evenly with the final 1 cup of reserved shredded cheese blend.

Step 6: Bake to Bubbly, Golden Perfection
Bake, uncovered, for 20-25 minutes, or until the cheese on top is completely melted, bubbly, and the edges of the chips are lightly golden. Watch closely to prevent the top chips from burning.

Step 7: Rest, Garnish, and Serve Fiesta-Style
Remove the bake from the oven and let it rest for 5-10 minutes. This allows the layers to set slightly for easier serving. Present the bake directly on the table, surrounded by small bowls of all your fresh garnishes. Provide a large serving spoon and instruct guests to scoop out portions and top them with their preferred fresh toppings