Heat 2 tablespoons neutral oil in a small saucepan over medium-high heat, until just hot glistening. This only takes a minute or two.
Add in 2 tablespoons flour, 1 tablespoon chili powder, 1 teaspoon ground cumin, ½ teaspoon onion powder, ½ teaspoon garlic powder, and ½ teaspoon dried oregano and whisk together until thick paste forms. Cook for one minute to toast spices and to rid of the sauce of a raw flour taste.
Whisk in 2 tablespoons tomato paste into the roux.
Gradually, whisk in 2 cups vegetable broth or chicken stock, whisking the entire time, until well incorporated and all lumps are removed. Reduce heat and simmer 10-15 minutes until slightly thickened. Remove from heat and whisk in ½ teaspoon kosher salt and 1 teaspoon white vinegar.
Use immediately or refrigerate in an airtight container for up to 5 days or freeze up to 3 months.
Notes
This recipe yields 2 cups. Nutritional information is based on the ENTIRE recipe. Most serving sizes are only 2-3 tablespoons.
Be sure to use regular chili powder. Not cayenne pepper or Ancho Chili powder, as the final result would be extremely spicy.
If you can't find Mexican oregano, regular dried oregano will work well.
Vinegar allows the flavors to really pop--don't overlook this ingredient.
If you find your sauce is at lumpy, you can strain it through a fine mesh strainer. You should not have any issues with lumps if you gradually whisked in the stock though.