This classic white wine sauce accented with mustard is excellent with pork or any grilled or roasted meat or poultry, as well as roasted vegetables.
2 tablespoons unsalted butter, divided
1/2 cup finely diced onions
1 cup dry white wine
3/4 teaspoon dry mustard, dissolved in a small amount of warm water
Up to 1/2 cup hot water
Salt and ground black pepper
Melt 1 tablespoon of the butter in a saucepan over medium heat, add the onions, and sauté them until they are translucent, 2-3 minutes. Add the white wine, bring the mixture to a boil, and cook until the wine is reduced to 1/2 cup.
Whisk in the Demi-Glace de Veau Gold® and the dissolved mustard, and then add enough hot water to thin the sauce to the desired conistency.
Strain the sauce and return it to the pan. Season to taste with salt and pepper, and whisk in the remaining tablespoon of butter.