The primary purpose of roasting chiles is to make the skin easy to remove. When chiles are roasted, the thin outer skin becomes blistered and charred, easily separated from the flesh. Roasting also softens the texture and gives a great aromatic smoky flavor to the chili pepper, especially when roasted over an open flame (or on a bed of hot charcoal, as traditional).
Small chilis can be roasted on an ungreased griddle or skillet or directly over an open flame, on your gas burner, depending on how large they are. usually, larger chiles are roasted.

Certain chilis, such as the poblano, are never eaten raw. They are roasted, sweated, and peeled to be used in recipes. Roasting is sometimes also called toasting. These are both the same thing, except when applied to dried chiles, which means a shorter toast on a griddle or skillet.
To Roast Small Chiles
Lay the chilis in an ungreased skillet over medium heat and turn them occasionally until the skins blacken in places and the chili becomes soft.
To Roast Large Chilis
You can roast large chiles on an outdoor barbecue grill, directly over the gas burner on your stove, or under the broiler in your oven.
The first two methods yield the best results. Although an electric burner can be used, do not place the chili directly on the electric element. You will have to hold it over the heat with tongs, which takes patience.
If you do not have a gas burner or barbecue grill, your best option is your oven’s broiler. If you are roasting a large amount of chiles but don’t have a grill, then the broiler, again is your best option.
It is also possible to roast chili peppers with a culinary torch, although this method is not the most efficient. To do so, place the chili on a stainless steel pan and hold the torch flame to the chili until the skin is charred and blackened. Move the flame around to roast the entire chili, turning the pepper with tongs as needed.
Gas Burner or Barbecue Grill Method for Roasting chile Peppers
Place the chilies directly on the grate over a medium heat on your gas burner, or directly over the hot coals in your outdoor grill.
Toast until the skin is blackened almost all over and there are few uncharred areas, turning occasionally with metal tongs to promote even blackening of the entire chili pepper.
Once they are blackened, immediately place them in a plastic bag or a covered bowl to sweat. This will help to further loosen the skins and to soften the chili through the residual heat.

Broiler Method
Place the chiles on a baking sheet and place a few inches under your oven’s broiler. Follow the same procedure as above, turning and blackening.
Chiles can also be roasted on the bake setting in your oven until they are thoroughly cooked and softened. This will concentrate the flavor and sweetness of the chili without blackening the skins.
Removing the Skins From Roasted Chiles
Once your chilis are thoroughly roasted and sweated, the skins should virtually fall off. All you have to do is rub them off with your fingers (they should be cool already).
If the skins are a bit stubborn, rubbing with a good quality paper towel, to provide friction, will help to get them off, or just rinse them under cold water while rubbing off the skins with your fingers.
Once your chiles are roasted and peeled, prepare them as per your recipe’s instructions.

Toasting Dried Chilis
Dried chiles can also be toasted. Cut off the end of the chili, just below the stem. There is usually a big clump of seeds in that area. These can be discarded.
Slit the chili down the middle and shake out the seeds, scraping out any that cling. You can scrape out the veins inside the chili by laying it out flat. The veins hold more heat so if you want more spice, leave the veins.
Lay the split-open chiles out flat in a skillet over medium heat. Press down with a spatula and toast just until slightly darkened.
When you hear a slight crackling and a bit of smoke rises, it’s time to turn the chili over. Don’t burn or char. Soak the chiles in a bowl of warm water or other liquid, depending on the recipe, to soften for about 30 minutes.
It is always up to you to toast your dried chiles if you’d like, even if the recipe does not call for it.
Never Roasted a Sweet Bell Pepper?
Well, you’ve never had a sweet bell pepper for real, then. Roasted bell peppers, green or red, like the ones in the image above, are a staple in the kitchen. It seems like anything that is good with bell peppers is better with roasted bell peppers.
I’ll tell you one of the best and simplest sauces you can make that can be used alone to top tons of stuff, including fish, or as a pasta sauce (you’ll flip, or as a base to build other sauces.
It also is a traditional finishing garnish for cream soups. Just a swirl on top adds the essential flavor of roasted peppers and a splash of color.
Or, if you like risotto, you can make a roasted rep pepper risotto like the one in the picture below.

This is a sauce that I believe needs to be kept simple. Experiment and add your own touches, but don’t over-complicate it. The idea is a sauce that tastes like roasted rep peppers, not a sauce with some roasted rep peppers in it.
The addition of shallots, garlic, and maybe some cilantro to the mix, blended well, and strained, will make a fantastic creamy rep pepper soup!
Just add more broth, and more cream, to your taste. A little bit of tomato paste is also good, although this can sometimes make too sweet a soup, so beware.
I am assuming you are going to roast your own peppers for this. As you can see from the instructions above, it is very simple, and although lots of recipes on the web call for canned or jarred roasted red peppers, they leave something to be desired.

Basic Roasted Red Pepper Sauce
Ingredients
2 med roasted red bell peppers
1/4 to 1/3 cup chicken or vegetable broth
2 tbsp melted butter
2 tbsp heavy cream (optional)
salt to taste
Instructions
Remove the stems and seeds from the roasted and sweated red peppers and carefully scrape away any excess membranes from inside the peppers (this will improve the flavor of the finished sauce). Cut or tear the peppers into chunks.
Place the red pepper pieces into a blender and add 1/4 cup of the chicken or vegetable broth along with the butter. If the broth is still hot, do not place the lid tightly onto the blender, but hold is loosely over the top to prevent splatter. Puree the pepper, broth, and butter mixture until as smooth as possible. Add the optional cream and blend a few seconds more. Check for thickness. If the sauce seems to thick, add a bit more of the broth and blend.
Now taste the sauce and add salt, if needed. Unless your broth is very salty, you probably will need to add some. Strain the sauce through a sieve, if desired. Use in your recipe as needed.