This method applies to all dried chilis. This works well if you want to stuffed them ( Ancho chilis), or simply blend them in a sauce.
1 - Cut off the stems and make a vertical slit. Pull open the chili and remove the seeds.
2 - Heat up a skillet. Use a spatula to press them into a DRY, hot pan (15/30 secs each side). It is really important that you do not burn them as they will taste bitter.
3 - Once they have been roasted, place them in a bowl and cover them with hot water ( not boiling). Let them soak for 20-30 minutes.