Put the vinegar, wine, shallot and pepper in a pan and boil until reduced to 2 TBS. Strain and set aside. Cream egg yolks with 1 TBS of butter and a pinch of salt. Turn off the heat and whisk the yolk mixture into the vinegar. Add 1 tablespoon of butter at a time. Add salt and pepper. Béarnaise sauce can be tricky so if it curdles, just whisk in a tablespoon of cold water. Dad always had a packet of Knorrs’ Béarnaise sauce on hand for back up :)
Recipe by The Energized Body at https://theenergizedbody.com/bearnaise-sauce/