The New Best Recipe from America's Test Kitchen
Makes about 3 1/2 cups
1 1/2 cups low-sodium chicken broth
2 Tbsp cornstarch
2 Tbsp unsalted butter
3 medium shallots, chopped fine
2 cups dry vermouth
1 Tbsp dark or light brown sugar
1/2 cup Dijon mustard
1/4 cup whole-grain mustard
1 Tbsp chopped fresh thyme leaves
Salt and pepper to taste
Whisk the broth and cornstarch together in a small bowl; set aside. Heat the butter in a 12-inch skillet over medium heat until foaming; add the shallots and cook until softened, about 3 minutes. Stir in the vermouth and brown sugar; increase the heat to medium-high and simmer until the alcohol vapors have cooked off, about four minutes.
Whisk the broth and cornstarch mixture to recombine, then gradually whisk it into the simmering liquid; return the sauce to a simmer to thicken, stirring occasionally. Off the heat, whisk in the mustards and thyme; season with salt and pepper to taste. (The sauce can be cooled to room temperature and refrigerated for up to two days. Reheat in a medium saucepan over medium-low heat.) Serve with ham.