Melt the butter. Use 8 tablespoons of butter for a thick hollandaise for dipping or dolloping; use up to 16 tablespoons to make a thinner, pourable sauce. Melt the butter in a small saucepan over medium-low heat.

Blend the yolks, lemon juice, and salt. Place the egg yolks, lemon juice, and salt in a blender and pulse to combine.

With the blender running, slowly stream in half the warm butter. With the blender running and the top open, slowly stream in the warm butter — start with a few drops, then a thin drizzle. Once you've added about half the butter, check the sauce (you can stop the blender if you need to). If it looks grainy or separated, see "Fixing a Broken Sauce,"

Continue adding butter in a steady stream. If the sauce is looking good, you can pour the butter a little more quickly in a steady stream. Continue pouring the butter and occasionally checking the sauce until the sauce is as thick or thin as you'd like, or you've added all the butter. When done, the hollandaise should be light yellow with a smooth, uniform consistency.

Taste and adjust the sauce. Stop the blender and taste a small spoonful. It should taste rich, buttery, and slightly tangy. Stir in a little salt, cayenne, or lemon juice, if needed. If the sauce seems a little too thick to you, blend in some water a tablespoon at a time until the sauce is as thin as you like it.

Serve the sauce. Hollandaise is best served as soon as it's ready, while still warm. If you need to, you can transfer the sauce to a double-boiler and keep it warm over low heat on a back burner, or set over a bowl of very hot water, for about an hour. The thicker and more mayonnaise-like the hollandaise, the more stable it tends to be; thinner sauces will break more easily — especially if they are held for too long before serving or if they get too cool. See "Fixing a Broken Sauce,"

Broken sauce: If your sauce does break, all is not lost. Here are a few things to try, in order of desperation: First, stop adding more butter, and let the blender run for about 30 seconds. If the sauce looks good, you can continue adding butter.

Broken sauce: Second, try blending in a few teaspoons of hot water. Run the blender for 30 to 60 seconds. If the sauce looks good, you can continue adding butter.

Broken sauce: Third, add another yolk: Pour whatever you have in the blender into a measuring cup. Add a yolk and a teaspoon of water to the blender, and start it running. Slowly stream your broken sauce into the blender with the new egg yolk. If it looks good, then you can keep adding the remaining butter.

If the finished sauce breaks before you serve it: It can be tricky to rescue a finished sauce that has broken during its wait for the breakfast table, but there are a few things you can try. If the sauce is still warm, transfer it to a blender and blend for 30 to 60 seconds. If the sauce has cooled, warm it for a few seconds in the microwave until it feels warm (not hot) when you touch the liquid with your finger, then blend it for 30 to 60 seconds. Serve this hollandaise sauce immediately.