Remove husks from tomatillos; rinse. Place tomatillos in large saucepan; add enough water to cover. Bring to a boil. Reduce heat to medium; cover and cook 8 to 10 minutes or until tender. Drain.
Place tomatillos in food processor bowl with metal blade or blender container; process with on/off pulses just until smooth.** In large bowl, combine tomatillos and all remaining salsa ingredients; mix well. Spread 1 cup of the salsa over bottom of ungreased 13x9-inch (3-quart) baking dish.
Heat oven to 350°F. In large bowl, combine chicken, 1 cup of the cheese, 1 cup of the salsa, green onions, cumin, chili powder and 1/4 teaspoon salt; mix well. Spoon 2 heaping tablespoons chicken mixture down center of each tortilla; roll up. Place, seam side down, over salsa in baking dish. Spoon 1/2 cup of the salsa over filled enchiladas. Cover.
Bake at 350°F. for 30 to 35 minutes or until thoroughly heated. Top with remaining salsa and cheese. Bake an additional 2 to 3 minutes or until cheese is melted.