Preheat oven to 375°F Preheat large sauté pan on medium 2–3 minutes.
Place turkey, onions and green chiles in pan. Brown ground turkey 5–7 minutes until meat is brown and no pink remains. Stir frequently and break meat up as it cooks. Drain, if needed. Stir in taco seasoning, water and potatoes, and cook another 3-5 minutes.
Assemble enchiladas as follows: lay tortilla flat and place 1/4 cup meat mixture on tortilla. Roll tortilla to form cylinder shape, arrange seam side down in 10x13-inch baking pan. Repeat with all tortillas.
Pour enchilada sauce over filled enchiladas. Sprinkle with cheese and bake 15 minutes.
Top with your choice of tomatoes, shredded lettuce and sour cream, if desired. Serve.