Melt the butter in a saucepan over medium heat.
Whisk in the flour and cook, stirring constantly, for about 1 minute.
Gradually whisk in the vegetable broth, ensuring there are no lumps.
Add the soy sauce, onion powder, garlic powder, and black pepper.
Bring the mixture to a simmer and cook until thickened, about 5-7 minutes.
Season with salt to taste and adjust other seasonings if necessary.
Serve warm over your favorite dishes.