The chile used to season tamales is the ancho . The ancho is the ripened, dried form of the poblano. It has a rich, smoky flavor. While other dried chiles can be used for seasoning, the ancho provides an authentic flavor. Traditionally, ancho alone is used but I like to use a combination of chiles for seasoning tamales.
T oast the dried chiles on a hot cast-iron griddle for a few minutes on each side.
Be careful not to burn the chiles or they will have a bitter taste. As the chiles toast, they will become soft and pliable and may puff up. Put aside to cool. The chiles will become very crisp and brittle when cooled. W hen cool, remove the seeds and stems and crumble into small pieces.