Dried Chiles require a little preparation in order to make them usable in a recipe.
First, wash chiles and cut off the stem.
Slit the chiles lengthwise and remove the seeds and veins.
Preheat a griddle or small saucepan over a medium heat.
Roast the chiles on both sides very lightly. Ensure not to burn them as this will produce an acrid taste.
Next, allow the chiles to soak in hot water for 20 to 30 minutes.
Drain chiles and then grind into a paste in a blender.
Pass them through a wire mesh strainer to remove any bits of skin.