Set the pan into the center of the oven and broil (400 degrees F) for 20 minutes, or until the skins of the tomatoes and peppers blister up. Do not allow to burn.
Makes about 2 cups. Serves 8 ¼ cups.
Heat Factor: Mild-Medium. You'll get some heat from the jalapeno pepper, but if you're looking for a spicier version that is still authentic and traditional, go with serrano peppers.