Instructions

  1. Roast the unpeeled garlic on an ungreased griddle or heavy skillet over medium heat, turning occasionally, until soft and blackened in spots, about 15 minutes; cool and peel.
  2. While the garlic is roasting, stem and seed the chiles.
  3. Toast the chiles on another side of the griddle or skillet, 1 or 2 at a time, opening them out flat and pressing them down firmly with a spatula.
  4. In a few seconds, when they crackle, flip them and press down to toast the other side.
  5. In a small bowl, cover the chiles with hot water, and let them rehydrate for 30 minutes, stirring frequently to insure even soaking.
  6. Drain.
  7. In a food processor or blender, combine the chiles and a 1/2 cup of water, along with the garlic, oregano, black pepper and cumin.
  8. Blend to a smooth puree, scraping down and stirring frequently (add more water if the mixture won't move through the blender).
  9. With a rubber spatula, press the chile mixture through a medium-mesh strainer into a bowl.
  10. Heat the oil in a 4-quart pot over medium-high heat.
  11. When hot, add the lamb and brown thoroughly, about 8 minutes.
  12. Add the chile puree and stir for about 5 minutes as the mixture thickens.
  13. Stir in beef broth and simmer until lamb is tender, about 2 hours.
  14. Add mushrooms, epazote, hot sauce and masa harina.
  15. Partially cover and simmer gently over medium-low, stirring frequently, until mushrooms are soft and the sauce has reduced to coat the meat rather thickly, about 30 minutes.
  16. Taste and season with salt.