Bring first 3 ingredients and 1 1/2 teaspoons salt to a boil in a Dutch oven. Cover, reduce heat, and simmer 30 minutes. Add tomatillos, and cook 5 more minutes. Remove chicken and tomatillos, reserving broth for Verde Sauce and Mexican Pinto Beans. Bone and shred chicken. Chop 7 tomatillos, reserving remaining tomatillos for Verde Sauce.
Sauté onion and garlic in hot oil in a Dutch oven over medium-high heat until tender. Add chopped tomatillos and remaining 1/2 teaspoon salt. Cook 5 minutes. Add chicken, and cook 5 minutes. Stir in cilantro and 1 cup Monterey Jack cheese.
Sprinkle 1 tablespoon water in tortilla package. Microwave at HIGH 1 minute.
Dip each tortilla in Verde Sauce. Place about 1/2 cup chicken mixture down center of each tortilla; roll up. Place in a lightly greased 13- x 9-inch baking dish; top with remaining sauce, spreading to ends of tortillas. Sprinkle with remaining Monterey Jack cheese and feta cheese. Cover and chill 8 hours, if desired; let stand at room temperature 30 minutes.
Bake, covered, at 425° for 25 minutes or until thoroughly heated. Serve with Red Pepper Purée.