Start up your grill. Then, set the temperature to 300F.
In a bowl, mix - the chicken, green chiles, Sweet Heat seasoning, sour cream, diced onion, and half the bag of shredded cheese.
Place a large spoonful of the chicken mixture in the center of a tortilla and roll it up. Repeat with the remaining tortillas, then place in the baking pan, and pour the enchilada sauce over the tortilla pans. Top with the remainder of the shredded cheese.
Wrap the top of the pan tightly in aluminum foil and grill for 45 minutes or until the enchilada sauce is bubbly. Remove from the grill and serve.