Place the chicken in a large pot, add enough water to cover, and bring to a boil.
Reduce heat and simmer until cooked through, 25-35 minutes; remove from pot and let cool.
Once the chicken is cool enough to handle, shred, discarding meat and bones.
Meanwhile, in a blender puree the salsa, cilantro and 1 cup of the sour cream until smooth. Transfer the puree to a saucepan to simmer the sauce until thickened, 15-20 minutes. Stir in the remaining cup of sour cream.
To the shredded chicken add the corn, 1 cup of the sauce, 1 cup of cheese and 1 teaspoon each of salt and pepper.
Spread 1 cup of the remaining sauce in two 9x13" baking dishes. Roll the chicken mixture in the tortillas (about 1/2 cup per tortilla) and place seam side down in the dishes. Top each dish of enchiladas with 1 cup of the remaining sauce and cheese.
Heat through in oven at 375F for 20-25 minutes.