In a medium saucepan heat oil over medium heat, add flour, smoothing and stirring with a wooden spoon.

Cook for 1 minute, then add chili powder and cook for 30 seconds.

Add stock, tomato paste, oregano, and cumin. Stir to combine. Bring to a boil, reduce heat to low and cook for 15 minutes, stirring occasionally.

The sauce will thicken and smooth out. Adjust the seasonings, adding salt as necessary.