Melt butter in a non-stick skillet or saucepan over medium heat.
¼ cup butter
Stir in the flour.
¼ cup all-purpose flour
Cook until the mixture is golden in color (about 5 to 7 minutes), stirring constantly. (You want it to bubble gently. If it is bubbling too vigorously, turn the heat down to medium-low.)
Slowly whisk in the broth, about ¼ cup at a time, until smooth. Bring to a simmer.
2 cups beef broth
Lower the heat to medium-low and simmer until thickened, about 2 to 3 minutes, stirring occasionally.
Stir in dry sherry, if using.
1-2 tablespoons dry sherry
Season with salt and pepper, to taste. Add some fresh herbs, if desired.
Serve.
Notes
Fridge Storage: You can store your leftover brown gravy in the fridge. It can last up to 4 days in the fridge in an airtight container, so eat quickly or send it to the freezer.
Freezer Storage: You can also freeze gravy for up to four to six months in the freezer. Store it in airtight containers or freezer bags, or freeze portions in ice cube trays so you don't have to thaw the whole container every time.
Reheating: Reheat on the stove over medium heat. Whisk in some extra broth if it has thickened too much.