To roast bell peppers: On a gas stove-top, cook the whole peppers directly over a medium-high gas flame until blackened on all sides, turning with tongs. If cooking under a broiler, place halved, cored and seeded peppers on a baking sheet, cut-side down. Broil 5 to 7 minutes or until the skin has blistered and blackened over the entire surface. Transfer peppers to a paper bag. Close bag. Let stand 15 minutes or until peppers are cool enough to handle. Peel off blackened skin.