Preheat oven to 425 degrees F.
In a medium bowl mix together the chicken, cilantro, red onion and reduced fat cheddar cheese.
In a small bowl add the eggs, milk, salt, pepper and garlic powder. Whisk it together.
Spray a 9″ pie pan with no-stick cooking spray.
Add the tortilla to the pie pan.
Next add the chicken mixture.
Pour the egg mixture over the chicken mixture, then sprinkle the mozzarella cheese on top.
Bake 20 minutes or until the egg mixture is set in the center.