Remove the stems and seeds from the anchos, pasillas, and guajillos.
Cover the chiles with boiling chicken stock and let them steam for about 30 minutes.
Blend the chiles and soaking liquid until smooth.
Cut the pork shoulder into ½” pieces, season with salt and pepper, and brown in a large pot.
Add garlic, bay leaves, ground cumin, fresh sage, and fresh oregano to the pot and stir until fragrant.
Add chicken stock and simmer uncovered for about an hour.
Stir in the chile purée and simmer for another 45 minutes.
Season with additional salt and pepper.
