Mustard-Cider Sauce
From America's Test Kitchen, Season 11: "Weeknight Workhorses"

Served with Sautéed Pork Cutlets. America's Test Kitchen uses boneless country-style pork ribs, which they cut and pound, to make their cutlets, but you could serve this with other types of pork.

1 tablespoon unsalted butter
1 small shallot , minced (about 2 tablespoons)
1 teaspoon unbleached all-purpose flour
1 teaspoon dry mustard
1/2 cup low-sodium beef or chicken broth
1/4 cup apple cider
1/2 teaspoon minced fresh sage leaves
2 teaspoons whole-grain mustard
Table salt and ground black pepper

Melt ½ tablespoon butter in small saucepan over medium heat; add shallot and cook, stirring frequently, until softened, about 1½ minutes. Add flour and dry mustard; cook, stirring constantly, 30 seconds. Slowly add broth, whisking constantly to avoid forming lumps. Add cider and sage and bring to boil. Reduce heat to low and simmer 5 minutes. Remove pan from heat, cover, and set aside while you cook your cutlets.

After cutlets are cooked (put in warm oven to keep warm), reduce heat under the skillet you cooked the cutlets in to medium, add reserved sauce, and bring to simmer. Cook, scraping pan bottom to loosen browned bits, until slightly thickened and reduced to about ½ cup, about 2 minutes. Stir in any accumulated pork juices; return to simmer and cook 30 seconds. Off heat, whisk in whole-grain mustard and remaining ½ tablespoon butter; season with salt and pepper to taste. Spoon sauce over pork and serve immediately.