Preheat oven to 220ºC .
Dust a clean work surface lightly with flour. Place entire dough on surface, spread it out, and flatten with fingers or rolling pin until you form a large rectangle (about 30 cm by 38 cm, and 1 cm to 1 cm thick). Dust sheet pan with flour and place dough on pan, stretching it to reach all sides. Using a kitchen spoon, smooth a thin layer of tomato sauce over pizza dough all the way to the edges. Sprinkle with olives. Place mozzarella and crumbled tuna over entire rectangle. Sprinkle with hot pepper and bake 20 minutes, or until golden brown on bottom and cheese is melted. Remove and serve immediately.