Step 1

Place brisket in a stovetop pressure cooker. Add onion, garlic, bay leaves, and salt; cover with water. Close cooker securely and place pressure regulator over vent according to manufacturer's instructions. Heat until steam escapes in a steady flow and makes a whistling sound, about 10 minutes. Adjust temperature until regulator is gently rocking. Cook for 60 minutes.

Step 2

Let pressure release naturally according to manufacturer's instructions, 5 to 10 minutes. Unlock lid and remove.

Step 3

Remove brisket from the pressure cooker and shred with 2 forks. Strain the cooking liquid, discarding solids. Measure 2 cups for the barbacoa sauce and save the rest for another use.

Step 4

Combine guajillo chile peppers and ancho chile peppers in a saucepan. Cover with water, bring to a boil, and cook for 5 minutes. Remove from heat and let stand in the hot water until softened, about 5 minutes. Drain.

Step 5

Combine softened chile peppers, vinegar, garlic, cloves, allspice, black pepper, oregano, thyme, cumin, ginger, cinnamon and reserved 2 cups cooking liquid; blend until thick and very smooth.

Step 6

Pour sauce into a heavy-bottomed pot over medium heat and season with salt. Bring to a soft boil; reduce the heat to low. Stir in shredded beef, coating completely with sauce. Cover pot and cook until flavors combine, at least 30 minutes and up to 1 hour.