Let me answer that question by giving you a few recipes.

First from The Neapolitan Recipe Collection (15th c) as seen here: http://medievalcookery.com/greneboke/recipes/macaroni.html:

Roman Macaroni. Out of fine flour make a dough that is a litttle larger than for lasagna, and wrap it around a stick, and cut the dough the dough the width of a finger so that it stays like a ribbon; set it to cook in good broth or in some other liquid depending on the season; let the liquid boil first with a little salt before putting the macaroni in it; and if they are cooking in water, add a little fresh butter to it.

And another recipe from there:

Vermicelli. Cook them in good fat broth for an hour, then set them out garnished with grated Parmesan cheese and mild spices; first make them yellow with saffron. You can make lasagna in the same way.

Here's another one from there, not shown on that site though:

Sicilian Macaroni. Make a dough of the whitest flour, one egg white and rosewater - and should you be preparing two plates of it, put in only two or three egg yolks; make this dough quite tough, and make small round sticks of it a hand’s width in length and the thickness of a straw; and get a fine iron rod a hand’s width in length and the thickness of a cord, set it on a pastry stick and give them a roll with both hands on a table; then draw out the rod and you have the macaroni hollowed through the middle; these macaroni should dry in the sun and can be kept for two or three years; cook them in water or a good meat broth, and garnish them with grated cheese when you set them out on plates with fresh butter and mild spices. Boil them gently for an hour.

Here's another one from Libro di cucina (15c):

LXIII - Ravioli ready to serve of herbs fantastic. If you want to make ravioli of herbs or of other manners, take herbs and peel and wash well; then boil it a little and pull them out and squeeze away all the water and chop with a knife and put in a mortar and take cheese fresh and strained, egg and spices sweet and strong and mix well together and make a paste and then take the thin pasta in the way of lasagne and take a large measure and make the ravioli. When they are make put to cook and when they are well cooked powder above enough spices with good cheese enough and they are good.

And just for good measure he's a French one from Ouverture de Cuisine (1604)

To make macaroni. Make paste with eggs & butter, & make large covers of the paste well held, & cut into bars the size of three fingers, & cut them like tripe, & put to boil like raviolis, & put full a plate with melted butter, parmesan & cinnamon thereon, well mixed together: & serve so, putting again a little cinnamon thereon.

So basically you'd cook the pasta in either water or broth for added flavour, then garnish it with butter, cheese, and spices. It's important to note that pasta with butter and cheese is still very common, and although we don't often use cinnamon on pasta (though it's still done some places) it's not uncommon at all to have nutmeg in modern sauces.

I haven't come across any cream sauces for pasta, though that doesn't mean they don't exist, but it seems that butter and cheese is the most common method.

Hi there, while you await more answers here, you may be interested in these older threads on the tomato in Italian cuisine:

• How did the Tomato come to be such an integral part of Italian cuisine?

• Italian cooking before the introduction of the tomato

• What was Italian food like in the 14th and 15th Centuries?

• What was Roman/Early Middle Ages food like in Italy?

• What were some Old World cuisines like before the Columbian Exchange?

• When did "traditional Italian" cuisine start and what made it happen? The Roman food is almost nothing like it.