Add the shallot, white wine, and white wine vinegar to a saucepan and bring to a boil.
1 shallot, ½ cup dry white wine, ¼ cup white wine vinegar
Reduce to a simmer and continue simmering until the liquid has reduced to about 2 tbsp.
Stir in the heavy cream and salt. Reduce the heat to low.
¼ cup heavy cream, ¼ tsp salt
Add in 2 cubes of butter and whisk until nearly melted. Repeat until all butter is used and incorporated. Take the pan off the heat.
1 cup unsalted butter
Pour the sauce through a strainer and into a bowl. Discard the shallot pieces.
Season with salt to taste. Serve and enjoy!