From Stuffed Blue Cheese Burgers

• 4 Tbs. unsalted butter
• 1/4 cup finely chopped shallots
• 1 cup lower-salt beef or chicken broth
• 3/4 cup red wine
• 1 Tbs. balsamic vinegar
• 2 tsp. Dijon mustard, preferably grainy
• Kosher salt and freshly ground black pepper

1. In a medium sauté pan, heat 1 Tbs. of the butter over medium heat. Add the shallots and cook, stirring often, until softened but not brown, about 2 minutes. Add the broth, wine, vinegar, and mustard. Increase the heat to high and bring to a boil, stirring frequently. Boil until reduced to 1/2 cup, about 9 minutes.
2. Off the heat, whisk in the remaining 3 Tbs. butter. Season to taste with salt and pepper. Serve warm.