Melt the butter in a large skillet over medium-high heat. Add mushrooms, salt, and pepper, and cook until golden brown.

Just before they're done add the garlic. Cook until fragrant, about 1 minute.

Add the wine and stir to loosen the brown bits from the bottom of the pan. Cook until almost entirely evaporated.

Add the chicken broth and cream. Lower the heat to medium and simmer until reduced by half, about 5 minutes.

Stir in the Dijon Mustard and more salt and pepper to taste.

Use as a sauce for pork, potatoes, and steamed vegetables.