Melt the butter in a large skillet over medium heat (or use pan drippings if available).
When melted, add the flour and mix to combine so no dry flour is left. Cook for 2 minutes.
Whisk in the milk, black pepper, salt, and garlic powder. Simmer, stirring occasionally, until the sauce begins to thicken, approximately 8-10 minutes.
Season to taste as desired and serve.
Notes
Traditionally, white gravy uses drippings from meat such as chicken or pork instead of butter as the fat. If you have drippings, use them! Use as much as the recipe calls for and discard the rest. If not, butter works great.If the gravy gets too thick, add a little water. If too thin, continue to cook.The gravy will thicken a little as it sits.