How to Make It
Roast the bell pepper over a gas flame or under the broiler until charred all over. Transfer the pepper to a bowl, cover with plastic wrap and let steam for 20 minutes. Peel the pepper, discarding the seeds and core. Finely chop the pepper.
Meanwhile, put the potatoes and carrot in a saucepan of cold water and bring to a boil. Cook over moderately low heat until tender, about 20 minutes. Drain and let cool.
Peel the potatoes. Cut the potatoes and carrot into 1-inch chunks and transfer to a bowl. Add the roasted pepper, eggs, tuna and olives. Fold in the mayonnaise and season with salt and pepper. Serve at room temperature or chilled.