In order to be great, steak needs a good sauce. It's not as hard as one would think!
1/4c white wine vinegar
1/4c dry white wine
3 tbsp minced shallots
1 tbsp chopped fresh tarragon
2-3 tbsp water
4 egg yolks
1 cup (2 sticks) unsalted butter, melted
juice of half a lemon
Bring vinegar, wine, shallots, and tarragon to boil in a small saucepan over medium-high heat. Boil until most of the liquid evaporates, about 5 minutes.
Off heat, add water, then whisk in egg yolks until frothy.
Gradually drizzle in butter, whisking constantly to incorporate. Sauce should be thick, but thin it with a little water if needed. If it's too thin, return it to low heat and whisk constantly until thickened.
Strain through a medium-mesh strainer into a heatproof cup. Season with lemon juice, salt, white pepper, and cayenne.