how long does it take to roast red peppers on the grill
1 Cook on the grill the same way. 2  If roasting in the oven, preheat to 450Â°F. 3  Arrange the peppers on a cookie sheet and roast in the oven, turning every 15 minutes until done (about 30 minutes).4  Whatever technique you use to blacken the peppers, once they are done, place in a covered bowl or brown paper bag. If roasting in the oven, preheat to 450Â°F. 2  Arrange the peppers on a cookie sheet and roast in the oven, turning every 15 minutes until done (about 30 minutes).