Preheat the oven to 425F. Place the peppers on a baking sheet and roast, turning occasionally, for 10 minutes or until the skins are almost blackened. Add the tomatoes to the baking sheet and bake for another 5 minutes.
Place the peppers in a plastic bag, close the top loosely, trapping in the steam, and then set them aside with the tomatoes until they are cool enough to handle.
Carefully pull off and discard the skin from the peppers. Remove and discard the seeds, then chop the peppers and tomatoes roughly and place them together in a mixing bowl.
Add the chili flakes, onion, garlic, lemon zest, and juice. Sprinkle on the parsley. Mix well, then transfer to a serving dish. Sprinkle with a little salt and pepper, drizzle on the olive oil, and sprinkle the olives and extra parsley on the top.