Heavy cream is usually labeled "Whipping" cream in most supermarkets.
Some will have what the call "freshly grated" tubs of parm in their deli. I would look for the closest to real (Not the green kraft shaker)

Heat up the cream till it comes to a low boil and let it reduce till you can start to see it thicken.
Now add your parm. (MAKE SURE TO CONTINUALLY STIR) Continue to stir till it looks a bit loose and turn off the heat.
The sauce will continue to thicken while, A) it cools or it mixes with the startch from the pasta.

Like previously stated you can start out with shallot/onion and garlic, deglaze with a dry white then start the cream.

http://allrecipes.com/recipe/quick-and-easy-alfredo-sauce/detail.aspx

Literally the best alfredo sauce I've ever eaten. I make this sauce every time I do something with alfredo now. I will never go back to a jar.

- make sure you read some of the comments before hand. They give a lot of insight into the recipe. (what to add/subtract from the recipe) You don't have to read them, but I have found listening to people who has made it before helps!

This post was edited by Dune1 on Mar 27 2012 10:10pm

creamy garlic sauce from papa murphy's >

heavy cream get hot. add garlic pepper parsley parmesan cheese a decent amount. let it thicking up keep cooking it then add noodles. turn heat down and enjoy

sometime you can add butter also but thats up to you, if making a big patch use corn starch slurry to thicken up

e/ why did not one person tell him to add any garlic to his alfredo ?

This post was edited by AriG0Ld on Apr 7 2012 09:39pm