In New Mexico, I believe they roast them first then they can peel the skin off. Even w dried peppers, they kinda dry roast them first.
Not sure what the best method of drying them is. I dry tomatoes low n slow in the oven. Never tried it w peppers.
If tomatoes get old, roast in oven w chili peppers onion and garlic until everything is blistered. Remove skins and I use immersion blender to make a sauce out of it - chefs trick.