Preheat the broiler. Roast the chiles under the broiler until charred all over. Transfer to a bowl, cover with plastic wrap and let steam for 5 minutes. Skin, stem and seed the chiles, then cut them into 1/3-inch dice. In a serving bowl, combine the chiles with the tomatoes, onion, olives, cilantro, olive oil and lime juice. Season with salt and pepper, toss to mix and serve.