Step 1

Trim excess fat from the roast and put it in the slow cooker.

Step 2

Break the stems from the guajillo chiles and shake out the seeds. Rinse the chiles and put them in a pot. Add 1 cup water and boil 5 minutes, or until soft. Drain and discard liquid.

Step 3

Put the chiles and everything else in a blender and puree.

Step 4

Pour this over the roast.

Step 5

Cover and cook 10 hours on low, or 5-6 on high or until beef is fork-tender.

Step 6

Shred the meat with two large forks and mix with the sauce.