Preheat your oven to 375°F (190°C).
In a skillet, heat olive oil over medium heat.
Add diced onions and sauté until soft.
Stir in the shredded chicken, garlic powder, cumin, salt, and pepper.
Spread a thin layer of green sauce on the bottom of a baking dish.
Place a tortilla on a flat surface and fill it with the chicken mixture.
Roll the tortilla tightly and place it seam-side down in the baking dish.
Repeat with the remaining tortillas and chicken mixture.
Pour the remaining enchilada sauce over the rolled tortillas and sprinkle with cheese.
Bake for 20-25 minutes until the cheese is melted and bubbly.