Preheat the oven to 375°F (190°C). Grease a 9 × 9-inch (23 * 23cm) baking dish.

In a large skillet, heat the oil over medium heat. Add the onion, green pepper, and garlic. Cook until softened, about 3 to 4 minutes.

Add the cream cheese and cumin to the skillet. Stir until the cream cheese is melted and smooth. Stir in the shredded chicken, and season with salt and pepper, to taste. Remove from the heat and set aside.

To make the sauce, in a medium bowl, whisk the salsa verde and sour cream until smooth.

Spread 0.5 cup (120ml) of the sauce in the bottom of the prepared baking dish.

Place 3 tortillas over the sauce, cutting them in half as needed.

Layer half of the chicken mixture, 0.5 cup (57g) cheese, 3 tortillas, and half of the remaining sauce. Repeat the layers, finishing with the remaining 3 tortillas and the remaining sauce.

Sprinkle the remaining 0.5 cup (57g) cheese over the top.

Bake for 23 to 27 minutes or until the cheese is melted and bubbly and the casserole is heated through.

Remove from the oven and let rest for 5 minutes. Garnish with chopped cilantro before serving, if using.