Preparation Place chicken and broth in heavy large pot. Bring to boil. Reduce heat to medium-low, partially cover pot and simmer until chicken is cooked, about 30 minutes. Cool chicken in broth. Strain broth and spoon off fat; reserve broth. Remove chicken skin and bones; discard. Shred chicken coarsely; transfer to large bowl. Heat 3 tablespoons oil in large saucepan over medium-low heat. Add 1 cup onion, garlic, oregano, cumin and cinnamon. Cover. Cook until onion is almost tender, stirring occasionally, about 10 minutes. Mix in chili powder and flour; stir 3 minutes. Gradually whisk in 4 1/2 cups broth. Increase heat to medium-high. Boil until reduced to 3 cups, stirring occasionally, about 35 minutes. Remove from heat. Whisk in chocolate; season with salt and pepper. Cool. Heat 1 tablespoon oil in medium skillet over medium heat. Add 1 tortilla and cook until just pliable, about 20 seconds per side. Transfer to paper-towel-lined baking sheet. Repeat with remaining tortillas, adding oil as needed. Spread 1/3 cup sauce in each of two 13 x 9 x 2-inch glass baking dishes. Mix 1 cup sauce into chicken. Arrange 8 tortillas on work surface. Spoon 3 tablespoons cheese, 1 tablespoon olives, 1 tablespoon onion and 1/4 cup chicken over center of each. Roll up tortillas. Arrange seam side down in 1 prepared dish. Repeat with remaining tortillas, 1 1/2 cups cheese, olives, onion and chicken. (Can be made 1 day ahead. Cover sauce and enchiladas separately; chill.) Preheat oven to 375°F. Top enchiladas with remaining sauce, then sprinkle with remaining cheese. Cover with foil; bake 20 minutes (30 minutes if chilled). Remove foil and bake until sauce bubbles, about 10 minutes. Let stand 10 minutes.
Preparation Place chicken and broth in heavy large pot. Bring to boil. Reduce heat to medium-low, partially cover pot and simmer until chicken is cooked, about 30 minutes. Cool chicken in broth. Strain broth and spoon off fat; reserve broth. Remove chicken skin and bones; discard. Shred chicken coarsely; transfer to large bowl. Heat 3 tablespoons oil in large saucepan over medium-low heat. Add 1 cup onion, garlic, oregano, cumin and cinnamon. Cover. Cook until onion is almost tender, stirring occasionally, about 10 minutes. Mix in chili powder and flour; stir 3 minutes. Gradually whisk in 4 1/2 cups broth. Increase heat to medium-high. Boil until reduced to 3 cups, stirring occasionally, about 35 minutes. Remove from heat. Whisk in chocolate; season with salt and pepper. Cool. Heat 1 tablespoon oil in medium skillet over medium heat. Add 1 tortilla and cook until just pliable, about 20 seconds per side. Transfer to paper-towel-lined baking sheet. Repeat with remaining tortillas, adding oil as needed. Spread 1/3 cup sauce in each of two 13 x 9 x 2-inch glass baking dishes. Mix 1 cup sauce into chicken. Arrange 8 tortillas on work surface. Spoon 3 tablespoons cheese, 1 tablespoon olives, 1 tablespoon onion and 1/4 cup chicken over center of each. Roll up tortillas. Arrange seam side down in 1 prepared dish. Repeat with remaining tortillas, 1 1/2 cups cheese, olives, onion and chicken. (Can be made 1 day ahead. Cover sauce and enchiladas separately; chill.) Preheat oven to 375°F. Top enchiladas with remaining sauce, then sprinkle with remaining cheese. Cover with foil; bake 20 minutes (30 minutes if chilled). Remove foil and bake until sauce bubbles, about 10 minutes. Let stand 10 minutes.