There are many methods that may be used for roasting chiles. An open flame is hands down the best method, preferably outdoors on a grill. Many times, however, if a grill is not available, I will use a plumbers torch (available at any hardware store for around $15-$20. Do not try this with smaller kitchen style torches meant for caramelizing creme brûlée or other smaller jobs. You need a stronger, wider flame spread to do the job and you most likely will run out of fuel before you finish your peppers using a smaller torch.) If neither of these are available, the same techniques below may be used using the broiler setting of your oven and placing the chiles on a sheet pan and turning with tongs when needed.
1. If available, wear disposable gloves to prevent capsacin containing oils from getting on the hands and burning more sensitive areas when touched.
2. Place chiles on a grill and roast about 3 minutes until skin begins to blister. Blistering the skin is essential, however you do not want to cook the flesh of the chile underneath.
3. Once blistered, turn with tongs. Repeat as necessary until all sides are blistered. Place in plastic bag or tupperware and allow to sweat for about 5 minutes. This will loosen the skin.
4. With dry paper towel, gently wipe the skin off of the flesh of the peppers. Note: Do NOT run them under water as this will also rinse essential oils from the flesh. If you wish a milder flavor in your dish, the seeds and inner pith (white fleshy ribs inside the chile may be removed to decrease the heat.
5. At this point, the roasted chiles are ready for use in your favorite recipe, or to seal and store in the freezer for later use. If kept airtight, they will keep for about year.