The jars of the stuff are everywhere. Glass jars with thick, white sauce. Alfredo with garlic. Alfredo with mushroom. Alfredo with four cheese. Alfredo with red peppers. Sun dried tomatoes. The list goes on and on. And the way we eat them is no different. One of my younger cousins will only eat pasta alfredo if there's chicken and garlic. A simple bowl of homemade pasta with white sauce? Nope. It won't be consumed by her.

The classic "Alfredo" isn't really alfredo sauce. It's a style of dressing pasta. It's just butter and cheese. Parmigiano-Reggiano cheese. If you do a Google search for "alfredo recipe," you'll come up with a lot more complicated recipes. You'll also notice a common theme in those recipes - cream. In the jarred sauces and many "alfredo sauce" recipes, cream is used as both an emulsifier and a thinning agent. The fats in cream can give a weak sauce a lot of the thick, rich, luxurious mouth feel of a good pasta. And if your alfredo is too thick, you have the extra water weight in the cream to thin it out a bit.

But there is another way. A better way. A faster and more delicious way. I'm going to borrow from Harold McGee here, and tell you to cook your pasta in a frying pan. Don't believe me? Check out this video. Once your pasta is cooked and hot, and with some of that liquid remaining the pan throw in 113g of butter (about 1 stick) and 130g of Parmigiano-Reggiano cheese. And toss the pasta, the butter, the cheese and the pasta water together. In this combination the cheese and the pasta water will act as emulsifiers and thickening agents. The cheese has some proteins that can help with emulsion, and the pasta water has  starches that make for good thickeners.

Edit - Someone asked if they still needed to salt the water for pasta. Yes. Always salt pasta water. You can also add black pepper, red pepper flakes, cooked mushrooms, etc. after tossing.