Here's What You'll Need
unsalted butter, shallot, dry white wine, white wine vinegar, lemon juice, heavy cream, salt
Heat butter in a nonreactive saucepan over medium heat. Add minced shallot and cook until translucent, about 2-3 minutes.
Pour in white wine, white wine vinegar, and lemon juice. Cook until mixture reaches a simmer. Reduce temperature to medium, let the sauce thicken. Add heavy cream, stir, then turn heat to low.
Add cold, cubed butter. Swirl the pan until butter has emulsified into the sauce. Repeat with remaining butter. Taste, then season with salt, as needed. Serve immediately.