Mix all dry ingredients together in a small bowl. Set aside.
Melt butter in saucepan/skillet on medium. Whisk in flour mixture to form the roux.
Immediately add in the milk and whisk to break up any clumps. Gently whisk continuously until gravy thickens (about 6-8 minutes).
*if gravy is too thick, add in a little milk--if it's too thin, add in a little flour. Gravy will thicken upon standing and a skin will form. Leave on simmer/low and stir occasionally to prevent skin from developing, if you prefer.