Turn the oven broiler on high and place the oven rack at its highest setting. Put the peppers on a cookie sheet lined with foil. Broil on one side for 5 minutes. Flip the peppers over and broil for another 5 minutes. Flip a third time and broil for an additional 5 minutes.
Remove the pan from the oven and place the peppers in a sealable plastic bag for 10 minutes to continue to steam (during the 10 minutes, you can get your sauce going and shred your cheese if needed).
After 10 minutes, carefully take the peppers out of the bag (they are still hot!) and place them on a cutting board. Remove the skins with tongs or your fingers if they are cool enough. Remove the seeds and stems and dice the peppers. Add the diced peppers and 1 cup of cheese in a bowl and combine. Set the bowl aside.
In your food processor or blender, add the tomatoes, onion, and garlic and blend until smooth and set aside.
In a medium saucepan over med-high heat, heat the olive oil. Add the flour and whisk together for about a minute to make a roux. Slowly pour in the broth, whisking the entire time.
Add the chili powder, salt, and cumin and continue to whisk to combine. Now add the blended tomato mixture, tomato paste, Worcestershire sauce, and cinnamon. Stir everything to ensure it is fully combined. Bring to a boil and then immediately lower the heat to simmer. Stir the sauce occasionally as you prepare the other ingredients. After the sauce has simmered for a while, add the salt and pepper to taste. TIP: If you want a smooth sauce, you can give it another round in the food processor or blender.
Move the oven rack to the middle setting and preheat the oven to 400ºF. Wrap your tortillas in a damp paper towel and microwave for 60 seconds to warm them up and make them easier to roll. Keep them wrapped in paper towels until you are ready to assemble.
Pour about a cup of the enchilada sauce at the bottom of an oven-safe pan or dish (I used my cast iron pan, but a casserole dish would work just fine too). Take each tortilla and add some of the pepper and cheese mixture to the middle, roll up and place the seam side down in your dish. Repeat until all of your enchiladas are rolled.
Spoon more of the enchilada sauce all over the top of the tortillas to ensure all of them have been coated completely. You will probably have some leftover enchilada sauce you can save or freeze for another meal. Don't feel like you have to use it all.
Cover the top with the rest of the cheese and place in the oven for 15 minutes. For the last 2 minutes, I put my broiler on so the cheese was nice and melted and a little browned on top.
Remove the pan from the oven and garnish with the green onions. Serve with sour cream and avocado. Enjoy!