Preheat and prep: Heat the oven to 350°F (175°C). Grease a 9x13-inch baking dish with butter or nonstick spray.
Crush the Doritos: Lightly crush the chips in the bag with your hands. Aim for a mix of small pieces and some larger chunks.
You want texture, not dust.
Mix the sauce: In a large bowl, whisk together cream of chicken soup, cream of mushroom soup, sour cream, chicken broth, taco seasoning, garlic powder, onion powder, and smoked paprika until smooth.
Add the chicken and tomatoes: Fold in the cooked chicken and the drained tomatoes with green chiles. Stir until everything is evenly coated.
Layer the casserole: Spread a generous layer of crushed Doritos across the bottom of the baking dish (about 1/3 to 1/2 of the bag). Spoon half the chicken mixture over the chips.
Sprinkle with half the cheddar and half the Monterey Jack. Repeat with another layer of Doritos, the remaining chicken mixture, and the remaining cheeses.
Bake: Cover loosely with foil (tent it so the cheese doesn’t stick). Bake for 20 minutes.
Remove the foil and bake another 10–15 minutes, until the edges are bubbly and the cheese is melted and golden.
Rest and top: Let the casserole rest for 5–10 minutes so it sets slightly. Add your favorite toppings like green onions, jalapeños, or a dollop of sour cream.
Serve: Scoop into bowls or onto plates. Pair with a crisp salad or simple roasted veggies to balance the richness.