I was making a cream sauce last night to put over tortellini. My choices of cream at the store were heavy whipping cream and half and half. I used both and it turned out watery. Which should I have used?
I can only guess based on what happened to you, but usually when a recipe calls for "cream" and don't distinguish, it usually means heavy whipping cream.
Tortellini is a typical pasta from the region on Emilia in Italy, a stronghold of Italian dairy. It is the region where Parmigiano cheese and the company Parmalat originated, for instance. It is also the region of Parma ham. No surprise this recipe brings all of that together.
The traditional recipe asks for Panna fresca liquida, which in Italy would look something like this, and would be in a refrigerated area in the supermarket. It has between 20-30% of fat and is fairly liquid.
The traditional recipe asks for cooked ham (optional), butter, Panna liquida fresca, Parmigiano, nutmeg, salt and pepper. Thus no flour. The trick for consistency is on the right quantity of Parmigiano (a lot!). After cooking the tortellini, drain well and mix in the sauce over low heat in a hob until the right consistency. The starch coming from the pasta will also help to thicken the sauce. One way to gauge is to first cook the pasta, add to the cooked cream and add Parmigiano over the low fire until you get the desired consistency.
The consistency is of course a question of taste. For example, in this recipe the famous Emilian chef Massimo Bottura uses 300g of Parmigiano (24 months) for 200g of cream. Very intense!
I use 35% whipping cream or 35% heavy cream for sauces (dairy section as well). If you want a thicker consistency, I have found adding arrowroot powder or flour is the best. You only need very little.