Lightly grease a 13x9x2-inch baking dish; set aside.
For sauce, in medium saucepan, mix undrained tomatoes, the water, the chopped onion, chipotle pepper, adobo sauce, (if you like), the cilantro, cumin, chili powder and half of the salt. Bring to boiling; reduce heat. Simmer, uncovered, for 15 minutes. Remove from heat; let cool for 5 minutes. Place in a blender or food processor. Cover and blend or process until smooth.
Meanwhile, in a large skillet, heat oil over medium heat. Add chicken; cook and stir until browned and no longer pink. Remove from heat; drain off fat. Stir in salsa, sour cream, lime peel, and the remaining salt.
To assemble enchiladas, spoon 1/2 cup sauce into bottom of prepared baking dish. Spoon about 3 tablespoons of the chicken mixture onto each tortilla near edge; roll up. Place tortillas, seam sides down, in prepared baking dish. Pour remaining sauce over all.
Cover and bake in a 375 degree F oven for 15 minutes. Uncover and sprinkle with cheese. Bake 10 to 15 minutes more or until heated through. Sprinkle with olives and green onions. Makes 8 servings.