Preheat oven to 400 degrees and line a baking sheet with parchment paper or aluminum foil. Roast tomatillos, jalapeños, onion and garlic cloves for 30 minutes, flipping midway to avoid excessive charring. Remove from oven and let it cool for 10 minutes. Add roasted ingredients to a food processor with cilantro and spices, and blend until smooth. Add salt and pepper to taste.

Reserve 1/2 cup of sauce. Pour the remaining sauce and chicken broth into a large skillet over medium heat. Allow to simmer for 3 minutes. Add shredded cheese and sour cream, and mix well until combined, allowing to simmer for an additional 3 minutes. Remove from heat and set aside.

Lower oven temperature to 350 degrees. In a small skillet, add vegetable oil over medium heat. Once warmed, add one tortilla at a time, leaving submerged for 5-7 seconds. Remove and place on a paper towel-lined plate.

In a large bowl, combine shredded chicken, 1 cup shredded cheese, and reserved 1/2 cup tomatillo sauce. Add two heaping tablespoons of the mixture to each tortilla, and tightly wrap them and place each in a 9 x 13 baking dish, seam side down.

Once all enchiladas are wrapped tightly, pour the roasted tomatillo sauce over the prepared baking dish. Sprinkle with remaining 1 cup of shredded cheese and bake for 10-12 minutes, or until cheese is melted and bubbly. Remove from oven and enjoy immediately.