Roast the chilies over an open flame until they are charred on all sides. Place in a plastic bag for 10 minutes to steam, then peel off the skin and remove seeds. Chop into small pieces.

Cut the pork tenderloin into bite-size pieces and cook in a cast iron skillet until browned on all sides.

In a blender, combine half of the chopped chilies with 4 cups of pork broth and blend until smooth.

Pour the chili-broth mixture over the cooked pork in the skillet and add in remaining chopped chilies, tomato sauce, and remaining pork broth. Stir to combine.

In a separate mixing bowl, make a roux by combining lard and flour until it forms a paste.

Add the roux to the skillet and stir until well combined.

Slowly add water to the skillet while stirring, until desired consistency is reached.

Let simmer on low heat for 8 hours, stirring occasionally.

Season with salt to taste.

Serve hot with rice or potatoes.