Preheat oven to 400°F. Unroll dough onto a baking sheet. Spread the sauce over the dough leaving a 1-inch border. Toss the vegetables with the olive oil and arrange over the pizza. Sprinkle with shredded mozzarella. Bake 30 min., or until crust is crisp and golden and vegetables are softened. Top with tuna and arugula.