Lemon Beurre Blanc Sauce

2 tablespoons freshly squeezed lemon juice
1/4 cup dry white wine
2 medium shallots, finely chopped
1 tablespoon crème fraîche
8 ounces (16 tablespoons) cold unsalted butter, cut into 16 pieces
Kosher salt, to taste
Freshly ground black pepper, to taste

Steps to Make It
Gather the ingredients.
In a medium saucepan over medium-high heat, bring the lemon juice, wine, and shallots to a boil. Continue boiling the mixture for 3 to 5 minutes, until it reduces and thickens slightly.
Add the crème fraîche and boil for an additional 2 minutes.
Lower the heat to medium-low. Add the butter, 1 cube at a time, and whisk, allowing each piece to fully melt before adding the next one.
When the last of the butter has just melted, remove the pan from the heat and strain out the shallots if desired.
Season the beurre blanc sauce with salt and pepper and serve immediately.

If you need to make the sauce ahead of time, keep it warm over very low heat, whisking every so often to keep the emulsion intact.
Make sure to lower the heat before adding and whisking in the butter; if the heat is too high, the butter will melt too quickly, and the sauce will not thicken properly.
For added flavor and color, sprinkle capers atop the finished dish.

Source: https://www.thespruceeats.com/lemon-beurre-blanc-sauce-recipe-1375315