1Preheat the oven to 400 degrees F (200 degrees C). Place the potatoes into a saucepan, and fill with enough water to cover. Bring to a boil and cook until tender, about 10 minutes. Drain.
2Place the peppers into the oven so that they sit directly on the rack. Roast, turning every 10 minutes or so, until evenly charred. Place in a paper bag to sweat, then remove the peel when they are cool enough to handle. Remove the stem and seeds, and chop.
3In a large bowl, combine the still warm potatoes, peppers, eggs, celery, onion, sweet pickles and olives. In a smaller bowl, whisk together the lime juice, vegetable oil, salt, pepper and mustard powder. I like to use a high speed mixing wand to help it emulsify. Pour over the potato salad, and stir to coat. Adjust seasoning to taste and serve.