Preheat your oven to 375°F (190°C) and grease a 9x12-inch casserole dish.

In a large skillet, heat olive oil over medium heat, add chopped onions and salt, and sauté for 5–7 minutes until softened.

Stir in minced garlic, chili powder, and cumin, and sauté for another minute.

Add cooked shredded chicken to the skillet, combining well, and continue cooking for 2–3 minutes.

In a mixing bowl, blend salsa verde and sour cream until smooth for the sauce.

Spread ¾ cup of the salsa mixture in the bottom of the greased casserole dish, layer 8 tortilla halves, followed by half the chicken mixture, 1 cup of salsa, and ½ cup of cheese.

Repeat with remaining tortillas, chicken mixture, another cup of salsa, and remaining cheese.

Bake in the preheated oven for 15–20 minutes until cheese is melted and bubbly.

Let the casserole rest for 10–15 minutes before serving.