Place a medium saucepan over medium heat and add the vegetable oil. Let it warm for about 30 seconds until slightly shimmering.

Add the flour to the hot oil and whisk continuously for about 1 minute. This helps thicken the sauce and removes the raw flour taste.

Stir in chili powder, cumin, garlic powder, onion powder, paprika, salt, and black pepper. Toast them briefly for about 30 seconds to release their flavors.

Slowly pour in the tomato sauce and water (or broth), whisking constantly to avoid lumps. Stir until the mixture becomes smooth.

Lower the heat and let the sauce simmer for 10–12 minutes, stirring occasionally. It will thicken and develop a rich red color.

Stir in the white vinegar at the end. Taste and adjust salt or spice levels if needed. Let it cool slightly before serving.