Consider roasted peppers a paradox -- you give them heat, they give you sweet. You can oven-roast any type of fresh pepper in two ways: slow and low or fast and fiery, depending on how firm or soft you want them. Slow-roasting tempers peppers' piquancy, caramelizes their sugars and concentrates their flavor to a sultry essence -- perfect for hot foods, such as pizza and pasta. Oven-broiling, on the other hand, blisters the peppers' skin, imparts a smoky aroma and preserves much of the peppers' firmness -- what you want for cold dishes, such as pickles and salads.
Soft and Sweet
Heat the oven to 350 degrees Fahrenheit, then scrub the peppers thoroughly under warm water with your fingers. The wax, pesticides and debris on the pepper surface create subtle, "off" flavors when heated.
Place the peppers on a baking sheet and set it on the middle oven rack. Roll the peppers on the pan so a different side faces up every 15 to 20 minutes.
Roast the peppers until they look wilted; about 1 hour for bell peppers, 35 to 45 minutes for jalapeno and banana peppers, and 15 to 30 minutes for chili peppers, depending on their size. Browning varies with humidity, so don't use color to determine the peppers' doneness; when they collapse, they're ready.
Place the peppers in a large bowl as soon as you take them out of the oven and cover it tightly with plastic wrap. Let the peppers steam for about 15 minutes.
Unwrap the bowl, place the peppers on a cutting board and slice them on one side. Open the peppers to pull the stems off or cut them away.
Scrape out the seeds and slice away the ribs and white pith. Cut the peppers to the desired size.
Firm and Fiery
Set the oven rack to the top position and start the broiler. Slice the peppers into quarters and scrape out the seeds.
Cut away the ribs and white pith. Place the peppers skin-side up on a baking sheet and slide it into the oven.
Broil the peppers until the skin chars, 6 to 12 minutes, depending on their size; bells take about 12 minutes, jalapenos take about 8 to 12 minutes, and chilis take between 3 and 5 minutes.
Place the peppers in a bowl as soon as you take them out of the oven and cover the bowl with plastic wrap. Steam the peppers for 10 minutes or until they're cool enough to touch, then peel away the skins and cut them to the desired size.