Add oil to a medium pot and place over medium-high heat. Once the oil is shimmering add the flour and whisk in then add the spices and continue whisking for a minute.
Pour in the tomato sauce and whisk then add the stock and continue whisking until slightly thickened.
Remove from heat and stir in the vinegar.
Notes
Looking for a mild enchilada sauce? If you don't want your sauce to be spicy you can reduce the amount of chili powder or omit it altogether.
If you'd like more heat then try adding in a pinch of cayenne pepper.
You can also add in a splash of heavy cream after the stock to make a creamy version of this sauce.
Make sure to cook the roux mixture for a few minutes to remove the raw flour taste but don't let it brown.
Use a whisk while you add the tomato sauce and stock to ensure there are no lumps in the sauce.
The cinnamon adds a subtle sweetness and warmth to the sauce but don't worry it's not a sweet tasting sauce.
The vinegar really enhances all the flavors so try not to skip it!