Right on the heat
Trim off any long stems and place the peppers directly over the grate of a gas stove. For electric stove cooks, Deborah Madison recommends placing one of those little mesh grills, an "asador," over the burner and roasting the peppers on that.
If you're preparing more than just a few peppers at a time, you can broil them. Small peppers (like the jalapeños pictured) can be broiled in a toaster oven. Rotate the peppers every few minutes to ensure that the skin is evenly blistered and blackened.
Use tongs to rotate the pepper so that it is evenly heated. After several minutes over a strong flame, they should be ready.
The optional steaming step
I usually skip this step, partly because I have no patience. But I also find it’s really not hard to peel the skin right away (or as soon as you can comfortably handle the pepper) if the skin is well-charred. If you see right away that it’s going to be difficult to get the skin off, however, put it in a covered container while the pepper is still very hot for about 10 minutes. The steam will loosen the skin a little more, softening the pepper a little further (which may not be a bad thing, especially if your pepper is not thoroughly charred).
Using a paring knife, gently scrape the skin off. There might be a couple of blackened bits remaining, but that’s nothing to fuss over—it’ll add flavor. And don’t think about rinsing the outside of the pepper—you’ll be sending the juiciness and smokiness down the drain.
Remove the core and seeds
Slice the peppers into the size and shape you need for your dish. Save the flavor-packed juice for sauces, soups, and dressings. (Remember to wash your hands thoroughly after handling spicy peppers, especially the seeds!)