In a small saucepan, gently melt the butter, over low heat, and bring to a simmer. As the butter is gently simmering, skim off the froth that accumulates on the surface of the butter. Simmer the butter for about 15 minutes, cool and ladle off the clear butterfat, leaving any milk solids in the bottom of the pan. This is clarified butter! Wow-who knew?
In a small saute pan combine the vinegar, white wine, peppercorns and shallots. Cook over medium heat until the liquid has almost all evaporated. Remove from the heat, add 1 large ice cube and let it melt. Strain the mixture through a fine mesh strainer into a medium-sized metal bowl. Add the 3 egg yolks and whisk vigorously to combine.
Put the metal bowl over a saucepan of barely simmering water. Whisk the eggs until fluffy, about 5 minutes. While whisking slowly drizzle in the clarified butter. Start with a couple drops at a time. If the eggs seem to be cooking too quickly, remove the saucepan from the heat. The idea of what is going on here, is that the eggs are being cooked ever so gently into a frothy, foamy deliciousness, not a scrambled curdled mess. Once all of the butter has been whisked in, add the fresh tarragon, and a pinch of cayenne. Season with kosher salt, to taste.
The sauce should be very full flavored, foamy and delightfully yellow. Serve on a big fat steak and call yourself a superstar!