Place chicken and next 5 ingredients in a large pot (6 if using cayenne). Fill with enough broth/water to cover the chicken by about an inch. Cover and bring to a boil over medium high heat. Reduce to medium low and simmer covered for 20 minutes.

When chicken is done, carefully remove from pot and place on cutting board to rest a few minutes before shredding. Remove cilantro from broth. Leave broth simmering lightly while you shred the chicken.

Use two forks to pull the chicken apart into shreds. When all the chicken is shredded return to pot. Slowly simmer in broth for 10 minutes more (to infuse with more flavor). Drain chicken in colander And get ready to assemble!

Assemble your layers! Preheat oven to 350°F. Spray 9x13" baking dish with nonstick spray. Pour 1/2 cup green enchilada sauce from the large can into baking dish. Swirl to coat bottom.

Place two tortillas on sauce, overlapping in the middle. Spread half of the shredded chicken on top of tortillas. Pour 1/2 of remaining enchilada sauce from the large can over chicken. Sprinkle 1 cup of cheese over sauce.

Repeat tortillas, chicken, sauce, cheese in same order once more, using the remaining chicken and last 1/2 of large can of sauce.

Top with last 2 tortillas, tucking edges down into dish on all sides. Sprinkle remaining cheese over top, then pour the entire small can of sauce over cheese to coat evenly. Lastly add black olives, if desired.

Tent loosely with aluminum foil, ensuring it doesn't touch the cheese on top. Bake in preheated oven for 30 minutes. Remove foil and bake 10 minutes more or until top is golden and bubbly. Let rest about 10 minutes before cutting. Top with desired garnishes, serve and enjoy!