What's the easiest way to make white sauce for pastas?

here's a nice recipe for an Alfredo sauce: "Alfredo" White Sauce 2 Tablespoons Butter, melted 3 tablespoons all-purpose flour 2 cups milk or half-and-half 1 medium to large clove garlic, minced 1/4 to 1/3 cup grated Parmesan cheese Freshly ground pepper, to taste Small pinch of nutmeg (optional) More grated Parmesan for garnish Minced fresh parsley (optional) Begin by melting the butter in the saucepan. Add the flour, a tablespoon at a time, whisking it into the butter each time to form a soft paste. Add the garlic, and cook the butter/flour/garlic mixture over medium heat for about 2 minutes, whisking constantly. It should be bubbly and thick, but not browned. Gradually add the milk or half-and-half, whisking the entire time. Tip: heat the milk in the microwave for a minute or so to warm it up (not too hot), to make it easier to combine with the butter/flour mixture. If you get a few lumps, just whisk them quickly and they should disappear. Increase the heat to medium high, and bring to a boil, whisking frequently, to keep the sauce smooth. When it reaches a boil, turn the heat down to a simmer, and continue simmering for another three minutes. Your sauce should be smooth and creamy and fully cooked at this point. Add the Parmesan cheese and whisk thoroughly until the cheese is completely incorporated and melted

White sauce, also known as Béchamel, is used in a variety of dishes and is the base for many sauces. Here are the steps for a basic medium white sauce, with adjustments for other thicknesses.This is very Easy and only takes 15 minutes. In a small, heavy saucepan, melt 2 tablespoons of butter over low heat. Blend 2 tablespoons of flour into the melted butter. Add 1/4 teaspoon of salt. Cook over low heat, stirring, for 4 to 5 minutes. Cooking for this length of time will minimize 'flour' taste. Slowly add 1 cup of milk, stirring constantly. Continue cooking slowly until smooth and thickened. For thin white sauce, follow the instructions above, but use 1 tablespoon of butter and 1 tablespoon of flour. Thin white sauce is used in cream soups. For thick white sauce, follow the instructions above, but use 3 tablespoons of butter and 3 tablespoons of flour. Thick white sauce is used in soufflés. For heavy white sauce, follow the instructions above, but use 4 tablespoons of butter and 4 tablespoons of flour. Heavy white sauce is used as a binder for croquettes. Tips: To make the standard Béchamel, after adding the milk to the medium white sauce recipe add 1 small onion studded with 3 cloves, a bay leaf, and a grating of nutmeg. Light stock, cream, or a combination may be used in place of the milk. Add more flavor by seasoning with celery salt, nutmeg, a teaspoon of lemon juice, onion juice, or sherry, or a few tablespoons of chopped chives or parsley . What You Need: Heavy saucepan 2 tbsp butter 2 tbsp flour 1/4 tsp salt 1 cup milk