Melt the butter in a saucepan over medium heat.
Add the flour and whisk continuously for 1-2 minutes until a roux forms.
Slowly pour in the broth while whisking to prevent lumps.
Bring the mixture to a simmer, continuing to whisk.
Let it cook for about 5-7 minutes until thickened.
Season with salt and pepper to taste.
Stir in any optional herbs for added flavor.
Remove from heat and allow to cool slightly before serving.
Store leftovers in an airtight container.
Reheat gently on the stove, adding broth if necessary.