Boil chicken breasts until cooked through.

Shred or cut the chicken into chunks.

Chop the onion.

Grate the Cheddar cheese.

In a saucepan, heat the cream of chicken soup (undiluted) with the chopped green chilies.

Place a portion of cheese, chicken, and chopped onion in a flour tortilla.

Add a spoonful of the cream of chicken soup mixture to the tortilla.

Roll up the tortilla tightly.

Place the rolled tortilla in a baking dish.

Repeat steps 6-9 with the remaining tortillas.

Pour the remaining sauce evenly over the enchiladas.

Sprinkle any remaining cheese on top.

Bake in a preheated oven at 400°F (200°C) for 20-25 minutes, or until bubbly and golden brown.