For the Roux: Melt ½ cup of lard in a pan and slowly whisk in ½ cup of flour until completely absorbed. Brown, stirring constantly, until roux is the color of peanut butter. Remove from heat and reserve until ready for chile.
For the Red Chile: Cut tenderloin into 1 inch cubes. Melt lard or oil in the bottom of a heavy stew or stock pot; add cubed meat and brown.
After meat browns, add red chile puree as well as garlic powder, cumin, oregano and salt; stir to combine. Bring to a boil, reduce heat and simmer for 20 minutes.
Add roux, mix well. The red chile broth should start to thicken and stick to the meat. Simmer for about 5 minutes.
Simmer on low heat for at least another 15-20 minutes (the longer the better!). The meat should become tender. Thin with beef broth to reach desired consistency. Remove from heat and serve.