To roast the peppers

1. Place an oven rack on the highest shelf below the heat element. Preheat to 400º F.
2. Meanwhile, line a large baking sheet with foil. Place a baking or cooling rack on the sheet. Lay all the peppers on the sheet, spaced equally.
3. Once the oven is fully preheated, insert the peppers. Turn the broiler function of the oven on, and set it to high. Allow to cook until the skin on the top half is black and blistered, 10-20 minutes or more. This will vary for different sizes, types, and ovens. For small peppers such as jalapeños or habaneros, decrease the time and watch the carefully.
4. Using tongs, turn peppers to roast all sides evenly, checking every 5 minutes or so. Continue turning until the skin on all sides is charred. If you’re cooking peppers of different sizes, feel free to remove faster-cooking peppers early so they don’t burn to a crisp.
5. As they finish, use tongs to carefully move the peppers to a large plastic container or bowl, and place a lid or plastic wrap on snugly. Allow the peppers to sit for half an hour, tightly covered. The steam will help separate the skin, making it easier for you to pull off.

To peel and de-seed the peppers

1. Carefully open the lid and move one pepper to a cutting board. Replace the lid immediately to keep the steam in.
2. Wearing gloves, pull off as much skin as possible. You can use a knife or spoon to help you lift and scrape off difficult parts, but you shouldn’t need it much. Remove the stem and the seeds attached to it, pull the pepper open, and remove the remaining seeds using a spoon.
3. Repeat these steps for all peppers. Use the peppers immediately, or refrigerate up to a week.