Bring a large pot of salted water to a boil. Add the pasta and cook as the label directs; drain but don't rinse. Meanwhile, combine the bocconcini, artichokes, marinated peppers and mint in a serving bowl. Add the olive oil, lemon zest and juice, and salt and pepper to taste and toss. Add the pasta and toss again. Just before serving, stir in the arugula and roast beef. Season the salad with pepper.