Using kitchen shears, cut off the stems of the chiles and cut them open. Remove the seeds and veins and discard.
Heat a cast-iron griddle or comal over medium, then dry toast them for ~30-60 seconds per side until fragrant.
Bring a saucepan of water to boil, then turn the heat off, add the pasillas in, cover the pot, and let the chiles rehydrate for 10-15 minutes until they feel soft and pliable.
Your chiles are now ready to be used in various Mexican soups, sauces, marinades, and moles.
Notes
The weight used in this recipe is an example only. The amount needed will depend on the size of the recipe.You can reserve the soaking water to use in recipes, but some people find it bitter, so always taste it first.Nutritional information is a rough estimate and should not be taken as health advice.