To make a simple Alfredo sauce, warm 1 stick of butter and 1 cup of heavy cream in a saucepan or skillet, and season it with salt and pepper. Add 2 cups of grated Parmesan cheese, and stir until it's melted.
Another simple Alfredo sauce recipe uses milk, eggs and Romano cheese. Heat 1 1/2 cups of milk and 1 1/2 cups of heavy cream in a saucepan until it starts to simmer, turn off the heat, and slowly whip in 1/2 cup of grated Parmesan cheese and 1/2 cup of grated Romano cheese. Place 6 egg yolks in a bowl, whip in some of the milk and cream mixture, and add it back to the remaining milk and cream. Put the pan over low heat, continue to stir it until it simmers, and take it off the heat until the sauce thickens. Season with salt and black pepper.
You can use Alfredo sauce in many dishes, including traditional fettuccine Alfredo as well as various pizza, vegetable, poultry and fish recipes. To serve it with pasta, toss it with cooked and drained noodles and transfer the pasta to a warm serving dish. Use the pasta water to thin the sauce if necessary, and sprinkle Parmesan cheese and parsley on top for added flavor.