Nice cafeteria/restaurant in front of the ancient Roman ruins of Torre Argentina. You can have quick meals but even pasta, pizza, meat. In summer you can sit outside.
Try their pizzas. They are not uncooked because it's the way of tradition to service meats (proscuitto for ex.) not cooked in pizzas. Nice place, sit outside if the weather allows.
uncooked food and bad service only stopped here because group wanted to eat right away.