In a separate small skillet or saucepan, melt the butter over medium heat.
Whisk in the flour to form a paste. Cook for 1-2 minutes, stirring constantly, until the raw flour smell is gone and the mixture turns a light golden color.
Slowly whisk in about 1 cup of the hot broth from the main pot into the roux. Whisk vigorously until smooth.
Pour this slurry back into the main pot. This method ensures a smooth, lump-free creamy texture.