Preheat and prep: Heat oven to 375°F (190°C).
Lightly grease a 9x13-inch baking dish. Stack tortillas and cut into quarters, or leave whole for layering.
Cook the aromatics: Warm olive oil in a large skillet over medium heat. Add diced onion and bell pepper; cook 4–5 minutes until softened.
Stir in garlic and cook 30 seconds until fragrant.
Brown the turkey: Add ground turkey, breaking it up with a spoon. Season with salt and pepper. Cook 5–7 minutes until no longer pink and lightly browned.
Season it right: Sprinkle in taco seasoning and stir to coat.
Cook 1 minute to bloom the spices. Add tomato sauce, diced tomatoes with chiles, and chicken broth. Simmer 3–5 minutes until slightly thickened.
Fold in the goods: Stir in black beans and corn.
Taste and adjust salt, pepper, or seasoning as needed. You want a saucy, well-seasoned mixture.
Layer the base: Arrange half the tortillas in the baking dish (overlap as needed). Spoon half the turkey mixture over them.
Sprinkle with 1 cup cheese.
Repeat: Add another layer of tortillas, the remaining turkey mixture, and finish with the last cup of cheese. For extra crunch, scatter a handful of crushed tortilla chips on top.
Bake: Cover loosely with foil and bake 15 minutes. Uncover and bake another 8–10 minutes, until the cheese is melted and bubbly and the edges are lightly crisp.
Rest and top: Let the casserole rest 8–10 minutes to set.
Top with chopped cilantro, sliced green onions, jalapeños, and a few lime squeezes. Serve with sour cream or Greek yogurt and avocado.
Serve: Scoop into bowls or plates. Add salsa on the side if you like extra heat.