How to Make It
Combine first 3 ingredients in a bowl.
Heat a large cast-iron skillet over high heat for 5 minutes.
Combine peppers and oil; toss to coat.
Arrange peppers in a single layer in pan; cook, without moving, 3 minutes or until skins are blistered and lightly blackened. Turn peppers; cook for 3 more minutes or until charred all over. Transfer to a plate, and sprinkle with salt. Serve with sauce.
You want to make sure the pan is extremely hot. Dense cast iron is ideal for charring: Once hot, it won't cool down when ingredients are added. Use only a small amount of oil--just enough to prevent vegetables from searing onto the pan surface and tearing when turned. Too much oil would create a barrier and cause the peppers to fry--you want them to char. Stirring would both cool down the pan and keep the peppers from making sufficient contact with the hot surface to blister and darken.