Heat oil in a skillet over medium-high heat. Stir in chili powder and flour, reduce heat to medium, and cook until fragrant and deepened in color, stirring constantly to prevent the flour from burning, about 1 minute.
Gradually stir in water, tomato sauce, cumin, garlic powder, and onion salt until smooth. Continue cooking over medium heat until thickened slightly, about 10 minutes. Season with salt.
Enjoy!
