Make your Mole Sauce: Heat a large skillet to medium heat and add a ¼ cup of olive oil. Add onion, garlic, cumin, oregano, cinnamon, salt and pepper. Cover and cook until onions are soft, about 5 minutes, stirring occasionally. Add the flour and chili powder whisking together until combined. Slowly add the broth, 1 cup at a time. Increase heat to high and boil until your sauce reduces down to about 3 cups. Be sure to stir occasionally to prevent your sauce from burning. Remove from heat and whisk in the dark chocolate. Set Aside.
For the chicken: Salt and pepper all sides of the chicken thighs. Add a ½ tablespoon of olive oil to a skillet over medium heat. Add chicken to the skillet and cover. Cook for about 4 minutes on each side until there is a nice browning on the chicken and it is cooked all the way through. Transfer your chicken to a cutting board and roughly chop.
To assemble the enchiladas: Place 1 cup of mole sauce on the bottom of your baking dish. Evenly distribute cheese and chicken among all 8 tortillas, then roll them up. Place each rolled enchilada in your dish, 4 along the top row and 4 along the bottom. Top with 1 cup of mole sauce. Cover with foil.
Bake in the oven at 375 degrees for 20 minutes. Remove foil and cook for another 10 minutes.
Serve with sour cream, sliced jalapenos, and cilantro.