Begin by making the chicken filling: In a Dutch oven over medium heat, heat the oil. Dry off the chicken thighs with paper towels and sprinkle on all the spices. Add a couple of chicken thighs at a time and brown on each side. Remove the thighs to a plate after they're browned. After all the chicken is browned put it back in the pot.
As the chicken browns, in a food processor, finely chop the cilantro, tomatoes, tomato paste, and chipotles. Add this to the Dutch oven, along with the browned chicken and the chicken stock. Simmer, covered, on low heat, for 50 minutes.
While the chicken braises, make the Green Chile Sauce : In a large skillet on low heat, heat the oil and cook the onion and garlic until it's soft, about ten minutes.
Add the tomato, green chilis, chicken stock, heavy cream, and spices. Simmer ten minutes, or until the sauce thickens up quite a bit. Remove the sauce from the heat and stir in the cheese.
Preheat the oven to 350 degrees, and grease a 9x11 baking dish with butter.
When the chicken is done, remove the chicken and shred it. Put the shredded chicken in a bowl. Stir in a cup of the braising liquid and the cheddar cheese.
Fill each tortilla with some of the filling, and roll it up. Place them close together in the baking dish seam side down. Pour the Green Chili Sauce over the rolled up tortillas, and then sprinkle on the cheese. Bake for twenty minutes.
Top the enchiladas with the tomatoes and sour cream and serve.