Stove or grill: Leave the pepper over the flame until the skin is completely charred. Rotate and char on each side. Don't forget the top and the bottom of the pepper as well.  Oven: If you are roasting in the oven, simply rotate the pepper a few times. The pepper is done when skin is lightly charred and the fruit is squishy to touch. For solid vegetables like squash and eggplant, it is done when the skin is tough and rubbery and the vegetable gives in to a light squeeze or a fork inserts easily into the tender flesh.