Since 1956, Marco, the self-proclaimed oldest pizzeria in Dallas, has been using a Sicilian family recipe currently known only to Frank Nuccio, son of founder Marco Nuccio. What is certain is that there are more than a dozen spices in the sauce and dough. What also keeps Marco's in business is its willingness to go with the flow. For example, among the available toppings are several vegan options. The specialty pizzas are many and varied. The Augustus is made up of an olive-oil glaze, freshly chopped garlic, spinach, sun-dried tomatoes, provolone and feta. The Special is a grocery list of ingredients: onions, sausage, ground beef, Canadian bacon, pepperoni, black and green olives, green pepper, mushroom, jalapeño and anchovy upon request. There are pasta dishes available, but with so many pies to choose from, a handful of noodles doused in sauce have a difficult time competing.