In a small saucepan melt the butter over medium-low heat. While the butter is melting, in a small bowl combine the flour, chili powder, onion powder, garlic powder, cumin, oregano, and sugar.
When the butter has melted add whisk in the spice mixture and cook for 1-2 minutes to bring out the flavor of the spices. Whisk in the vegetable broth and tomato sauce and cook until thickened slightly. Should lightly coat the back of a spoon.