Preheat oven to 375°. Heat the rolls in the oven for about 5-7 minutes. Meanwhile, heat the sausages over medium-high heat until fully warmed, about 5 minutes. Cut the roll in half, and slather the bottom half of the bread with the olives, then sausage, peppers, Havarti and finally, the arugula. Sandwich it with the other roll half and enjoy.