Char peppers on all sides over a gas flame until skin is blistered evenly all around. (If you don’t have a gas stove, char them under the broiler.) As each of the peppers are roasted, place them in plastic bag and let them sit for 5 minutes. This helps loosen the skin to make them easier to peel. When they’re cool to touch, rub the charred skin off with the back side of a knife blade. Remove stem, inner ribs, and seeds.