In a medium saucepan, combine the white wine, white wine vinegar, and minced shallots. Bring to a boil over medium-high heat and cook until the liquid is reduced to about 2 tablespoons, stirring occasionally, for about 10-12 minutes.

Turn the heat to low, and whisk in the butter a few pieces at a time until the sauce is smooth and emulsified. Keep whisking until all of the butter is melted and incorporated, about 2-3 minutes.

Remove the pan from the heat and season the sauce with salt and freshly ground black pepper, to taste.

Strain the sauce through a fine-mesh sieve into a bowl or a warm serving dish. Keep the sauce warm until ready to serve.