The most important thing you need to know about this light sauce is that it comes together with just three ingredients and less than 10 minutes on the clock.
Melt 1 tablespoon unsalted butter in a medium saucepan over medium heat. Add 1 tablespoon all-purpose flour, and cook, whisking constantly, until frothy but not darkened in color, 1 to 2 minutes.
While whisking constantly, slowly pour in 1 cup low-sodium chicken broth and keep whisking until smooth. Bring to a boil over high heat. Reduce the heat to maintain a simmer and cook, stirring occasionally, until slightly thickened enough to coat the back of a spoon, 2 to 3 minutes. Season with1/4 teaspoon kosher salt and a few grinds of black pepper. Taste and season with more kosher salt as needed.