Bearnaise Sauce (Blender)

METHOD
1 Place butter in a glass jug, and melt in the microwave, about 30 seconds on High.
2 With a hand blender and a container, Blend yolks, lemon juice and white vinegar for about 15 seconds.
3 Add melted butter slowly to the egg mixture while blending.
4 Add the Cream a bit at a time and blend until just mixed in. Do NOT thin the sauce to much.

NOTE:
1 You can use any of the following herbs Dried Tarragon, Dill or Chives.
2 The melted butter should be (60 to 63ºC) when adding to the egg yolk mixture.
3 If the sauce is to thick then thin it out a Teaspoon at a time with water or cream
   or some thing thin of some sort.
4 If the Bearnaise sauce thickens up too much as it sits, whisk in a tablespoon or two of hot water (NOT Boiling) or some more cream.
5 To keep the sauce warm keep it in a bowl and sit it over a warm saucepan (NOT BOILING) of water.

WARNING: A lot of blogs say just throw the extra away because of the egg yolks, though you maybe able to reheat if your inclined too as below.

Reheating Bearnaise:

Exert from Chef Talk Blog:

Over the weekend I did a search on google about “how to reheat hollandaise” and up popped my post first thing.  So I had some hollandaise left over in the fridge and I didn’t want to throw it out.  To me, hollandaise is expensive stuff with all the yolks and butter in it!  When I first posted this I believe I threw out my perfectly good hollandaise because I didn’t want to reheat it.  But this time I stuck it in the microwave.  Heated for 5sec and stirred.  Another 5sec and stirred.  I did this about 4 times until the hollandaise was warm.  It didn’t split, it held together and it was delicious the next day.  So, there is a way.  I stopped using cornstarch long ago though, don’t do that anymore.