Peel and finely mince the Shallot.
Combine the minced shallot with Dry White Wine and White Wine Vinegar in a small saucepan over medium heat and bring to a gentle simmer.
Reduce the mixture until almost all the liquid has evaporated and you’re left with a few tablespoons of concentrated shallot liquid—this intensifies the flavor.
Lower the heat to very low and begin adding cold, cubed Unsalted Butter a few pieces at a time, whisking constantly to emulsify; continue until the sauce is smooth and glossy.
Remove the pan from the heat once the sauce is thick and cohesive (do not let it boil), then season to taste with Sea Salt and a pinch of White Pepper.
If you prefer a perfectly smooth sauce, strain out the shallots through a fine mesh sieve before serving. Keep the beurre blanc warm (over a bowl of warm water or on the lowest heat) and serve immediately.
