Pre-heat oven to 350°F.
Season chicken breast with taco seasoning.
Place in oven and bake for 25 – 30 minutes or until cooked through.
Remove from oven and, using two forks, shred.
In a medium bowl. combine chicken, onion, sour cream and 1 cup of cheese.
Fill tortillas with chicken mixture.
Roll, and place, seam side down, in a 13 x 9-inch baking dish that has a small amount of enchilada sauce coating the bottom.
Pour remaining enchilada sauce over the top.
Cover with foil and bake for about 35 minutes, until bubbly and warm.
Remove from oven, uncover, sprinkle with remaining cheese and return to the oven for 5 minutes, or until cheese is melted.
Allow to cool for 5 minutes before serving as this makes them easier to remove from the pan.
